Every living organism relies on a genetic blueprint encoded in its DNA, yet the amount of DNA - or genome size - varies dramatically across the tree of life.&nbsp;



In animals alone, genome sizes range from the minuscule genome of Intoshia variabili, a marine parasite - which is about 200 times smaller than the human genome - to the massive genome of the marbled lungfish (Protopterus aethiopicus) - which is over 40 times larger than ours.&nbsp;



Plants exhibit a similar range, with the fork fern (Tmesipteris oblanceolata) setting the record with a genome size over 50 times larger than that of humans.



This diversity in <a href="https://www.earth.com/news/genome-mapping-completed-for-dozens-of-common-animals/" target="_blank" rel="noreferrer noopener">genome</a> size reveals the vast variety of life forms on Earth, but it also raises a fascinating question: If smaller genomes lead to faster, more efficient growth, why do some species have larger genomes?



<h2 class="wp-block-heading" id="h-advantages-of-smaller-genome-sizes">Advantages of smaller genome sizes</h2>



The replication of DNA is essential for cell production and growth, making smaller genomes more efficient as they require fewer resources and time to replicate.&nbsp;



Smaller genomes demand fewer <a href="https://www.earth.com/news/excess-nutrients-are-creating-ocean-dead-zones/" target="_blank" rel="noreferrer noopener">nutrients</a>, especially the DNA-building elements nitrogen and phosphorus, making them ideal for rapid growth and reproduction.



Because of these advantages, it’s not surprising that most species have evolved with relatively small genomes.&nbsp;



However, large genomes persist in some organisms, suggesting that these genomes may confer certain benefits in specific environments, where the costs of carrying extra DNA are outweighed by unique growth advantages.



<h2 class="wp-block-heading" id="h-exploring-large-genome-benefits-in-grasses">Exploring large genome benefits in grasses</h2>



A research team led by the <a href="https://www.sheffield.ac.uk/" target="_blank" rel="noreferrer noopener">University of Sheffield</a> has recently studied the potential benefits of large genomes in grass species. 



<a href="https://www.earth.com/news/fairy-circles-kill-all-newly-planted-grasses-deepening-their-mystery/">Grasses</a>, a vast plant family found worldwide from arctic tundras to tropical savannas, vary in genome size, making them an ideal group to examine how genome size affects growth in different conditions.



The study, published in the journal <a href="https://doi.org/10.1111/nph.20150" target="_blank" rel="noreferrer noopener">New Phytologist</a>, examined the growth of various grass species under conditions mimicking their natural environments - high temperatures, low nutrients, and drought. 



The scientists compared growth rates to each species’ genome size and observed that while grasses with smaller genomes generally grew better across most conditions, larger genomes provided advantages in two specific scenarios.



<h2 class="wp-block-heading" id="h-large-genomes-thrive-in-nutrient-rich-environments">Large genomes thrive in nutrient-rich environments</h2>



The first scenario where larger genomes proved beneficial was in nutrient-rich soils. While low nutrient levels slowed down large-genome grasses, those with large genomes thrived in high-nutrient environments.&nbsp;



Here, the extra DNA content meant larger cells that produced more biomass, such as leaves, which allowed these plants to outgrow and overshadow neighbors with smaller genomes.&nbsp;



In nutrient-poor areas, however, the demands of replicating additional DNA outweighed these benefits, making smaller genomes more favorable.



<h2 class="wp-block-heading" id="h-growing-seasons-and-genome-sizes">Growing seasons and genome sizes</h2>



The second advantage for large-genome grasses occurred in cooler environments, such as temperate regions with lower growing season temperatures.&nbsp;



<a href="https://www.earth.com/news/how-do-plants-grow-more-branches-and-become-bushy/" target="_blank" rel="noreferrer noopener">Plant growth</a> typically has two stages: cell division, where new cells are generated, and cell expansion, where cells swell with water to help the plant grow taller or spread. 



Cool temperatures significantly slow down cell division, but they have less impact on cell expansion.&nbsp;



Consequently, grasses with larger cells, which accompany large genomes, can expand more rapidly by cell enlargement even in cooler weather, outpacing smaller-genome plants that rely on faster cell division in warmer temperatures.



This cell expansion process explains the early spring growth of plants like daffodils and bluebells, which also have large genomes.&nbsp;



These plants perform much of their cell division in warmer months, allowing them to use cell expansion to grow quickly in early spring, well before smaller-genome plants begin to compete for light and nutrients.



<h2 class="wp-block-heading" id="h-genome-size-diversity">Genome size diversity</h2>



The diversity in genome sizes among grasses may be one reason for their global success, as it allows them to adapt to a wide range of environmental conditions.&nbsp;



While smaller genomes typically support efficient growth, larger genomes offer unique advantages in specific environments, enabling certain species to thrive where others cannot.&nbsp;



This genetic diversity in grasses underscores the importance of variation in supporting species’ survival and adaptability across ecosystems.



<h2 class="wp-block-heading" id="h-genome-size-and-evolutionary-success">Genome size and evolutionary success</h2>



The relationship between genome size and survival is not limited to plants. Our own medium-sized genome has supported humanity’s adaptability, though we don’t face the same nutrient limitations as stationary plants.&nbsp;



Unlike grasses, humans can move to seek out food and resources, which may allow us to bear the metabolic costs associated with our DNA without significant limitation.&nbsp;



This mobility highlights how different species leverage their genetic make-up in conjunction with unique behaviors and environmental interactions to thrive across diverse habitats.



In summary, the role of genome size in evolutionary success is nuanced and complex.&nbsp;



From the efficient replication of small genomes to the adaptability enabled by larger ones, genome size continues to shape the ecological <a href="https://www.earth.com/news/asian-forests-proving-resilient-both-climate-change-human-actions/" target="_blank" rel="noreferrer noopener">resilience</a> and global distribution of life on Earth.



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How does genome size impact evolutionary success?

Every living organism relies on a genetic blueprint encoded in its DNA, yet the amount of DNA - or genome size - varies dramatically across the tree of life.&nbsp; In animals alone, genome sizes range from the minuscule genome of Intoshia variabili, a marine parasite - which is about 200 times smaller than the human genome - to the massive genome of the marbled lungfish (Protopterus aethiopicus) - which is over 40 times larger than ours.&nbsp; Plants exhibit a similar range, with the fork fern (Tmesipteris oblanceolata)...

Important scientific discoveries often come from the most unassuming sources. Such is the case with a modest, 6-centimeter-wide fossil of bone and teeth discovered on a Texas beach that belonged to a prehistoric large cat. 



Initially, this fossil might not catch the eye, looking more like a nondescript, lumpy rock than a window into the past. However, its ordinary appearance belies its significant contribution to our understanding of <a href="https://www.earth.com/news/fossils-highlight-dinosaur-diversity-in-prehistoric-patagonia/" target="_blank" rel="noreferrer noopener">prehistoric life</a>.



<h2 class="wp-block-heading" id="h-fossil-s-hidden-secrets">Fossil's hidden secrets</h2>



John Moretti, a doctoral student leading the research at The University of Texas at Austin's <a href="https://www.jsg.utexas.edu/" target="_blank" rel="noreferrer noopener">Jackson School of Geosciences</a>, found the fossil to be more intriguing upon closer inspection. He compared it to a geode - unremarkable on the outside but holding valuable secrets within.



An X-ray conducted at the university's Computed Tomography Lab revealed an unerupted hidden canine tooth nestled within the jawbone, a critical clue to identifying the fossil's origins.



<h2 class="wp-block-heading" id="h-valuable-clues-in-a-saber-tooth">Valuable clues in a saber tooth</h2>



This particular fossil was determined to be from a Homotherium, a genus of large cats that roamed the Earth for millions of years.



The presence of the unerupted tooth, indicative of a juvenile not yet fully matured, was crucial. This stage of development meant the tooth was protected from damage, unlike fully erupted teeth which could have been broken off and lost.



"Had that <a href="https://www.earth.com/news/smilodon-fatalis-young-saber-toothed-cats-had-double-fangs/" target="_blank" rel="noreferrer noopener">saber tooth</a> been fully erupted and in its adult form, it would have just snapped right off," Moretti explained. "It wouldn’t have been there, and we wouldn’t have had it to use as evidence."



<h2 class="wp-block-heading" id="h-insights-from-the-cat-fossil">Insights from the cat fossil</h2>



Homotherium was not only a large cat but also robust, resembling a jaguar in size, with an elongated face and a distinctive sloping back that ended in a bobtail. These cats had serrated canine teeth covered by large gum flaps, similar to those seen in domestic dogs today.



The discovery of this particular large cat fossil on the now-submerged continental shelf connecting Texas and Florida provides new insights into the region's past ecology.



This area, which is believed to have been a Neotropical corridor during the Late Pleistocene, likely facilitated the movement of various animals including capybaras and giant armadillos from Mexico through Texas to Florida.



The presence of big carnivores like Homotherium would have played a significant role in controlling prey populations and shaping the <a href="https://www.earth.com/news/u-s-biodiversity-crisis-more-than-a-third-of-species-are-threatened/" target="_blank" rel="noreferrer noopener">biodiversity</a> of the region.



<h2 class="wp-block-heading" id="h-connecting-past-and-present">Connecting past and present</h2>



The cat fossil's journey from discovery to scientific revelation spans over six decades. Initially found by Russell Long, a professor at <a href="https://www.lamar.edu/" target="_blank" rel="noreferrer noopener">Lamar University</a>, it was later donated by U.S. Representative Brian Babin, a former student of Long's and a trained dentist.



Babin's unique background in paleontology and dentistry enabled him to recognize the true nature of the fossil.



"Without question, my professional knowledge and what I’ve learned as a dentist helped me in that regard," Babin noted, highlighting the interdisciplinary contributions that often aid in such discoveries.



The research is part of a broader study on McFaddin Beach fossils initiated in 2018, involving multiple co-authors and institutions. This collaborative effort underscores the collective endeavor of science to piece together the complex puzzle of our planet's ancient history.



<h2 class="wp-block-heading" id="h-lost-group-of-large-cats">Lost group of large cats</h2>



Homotherium, commonly called the "scimitar-toothed cat," is an extinct genus of large <a href="https://www.earth.com/news/two-new-species-of-sabertooth-cat-discovered-in-south-africa/" target="_blank" rel="noreferrer noopener">saber-toothed cats</a> that lived during the Pleistocene epoch. These formidable predators roamed across multiple continents, including North and South America, Europe, Asia, and Africa, for over 5 million years.



Unlike their famous relatives, the Smilodon (saber-toothed tiger), Homotherium had shorter, serrated canine teeth and a more robust, muscular build. Their teeth were adapted for slicing through flesh, indicating they were highly efficient predators.



The large cat's <a href="https://www.earth.com/news/declawing-large-cats-is-a-cruel-practice-with-shocking-impacts/" target="_blank" rel="noreferrer noopener">physical features</a> included an elongated face, a sloping back, and elongated limbs, suggesting they were built for endurance running.



These adaptations likely made the cats successful pack hunters, capable of chasing down large prey such as mammoths, rhinoceroses, and other large herbivores. Their presence in diverse environments, from open plains to coastal regions, demonstrates their adaptability.



<h2 class="wp-block-heading" id="h-extinction-of-homotherium">Extinction of Homotherium </h2>



The extinction of Homotherium around 10,000 years ago coincides with significant climate changes, human expansion, and the extinction of many large prey species. 



These factors likely contributed to their decline. Despite their extinction, the large cat's fossils continue to provide valuable insights into prehistoric ecosystems and predator-prey dynamics.



As more findings like this come to light, they enrich our understanding of the natural world and its former inhabitants. Each piece of bone or tooth, no matter how small or unappealing, could be the key to unlocking secrets of the Earth's vast, untold past.



The study is published in the journal <a href="https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.25461" target="_blank" rel="noreferrer noopener">The Anatomical Record</a>.



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"Ugly" fossil find reveals secrets of large prehistoric cats

Important scientific discoveries often come from the most unassuming sources....

Science,And,Research,Of,The,Universe,,Spiral,Galaxy,And,Physical

For centuries, scientists have grappled with the fundamental forces that govern our universe, chief among them being gravity, and more recently, dark matter. 



Gravity is the invisible force that attracts objects with mass towards each other, playing a crucial role in <a href="https://www.earth.com/news/cosmic-glitch-in-gravity-expands-the-theory-of-general-relativity/" target="_blank" rel="noreferrer noopener">shaping the cosmos</a>, from the formation of galaxies to the orbits of planets. 



However, as our understanding of the universe has expanded, so too have the <a href="https://www.earth.com/news/visible-matter-dark-matter-evolved-together-big-bang/" target="_blank" rel="noreferrer noopener">mysteries surrounding it</a>.



<h2 class="wp-block-heading" id="h-dark-matter-dilemma">Dark matter dilemma</h2>



One of the most perplexing of these mysteries is the concept of dark matter, a <a href="https://www.earth.com/news/dark-matter-does-not-exist-universe-27-billion-years-old-study/" target="_blank" rel="noreferrer noopener">hypothetical form of matter</a> that is believed to make up a significant portion of the universe's total mass. 



<a href="https://www.earth.com/news/microscopic-primordial-black-holes-may-explain-all-dark-matter-in-universe/" target="_blank" rel="noreferrer noopener">Unlike ordinary matter</a>, which we can see and interact with directly, dark matter does not emit, absorb, or reflect light, making it invisible to telescopes and other detecting instruments. 



Dark matter's existence, first suggested by Dutch astronomer <a href="https://en.wikipedia.org/wiki/Jan_Oort" target="_blank" rel="noreferrer noopener">Jan Oort</a> in 1932, is inferred solely from the gravitational effects it exerts on visible matter, such as the rotation curves of galaxies and the motion of galaxies within clusters. This leads scientists to question the very nature of gravity itself. 



These observations suggest that there is far more matter present in the universe than can be accounted for by visible matter alone. 



Despite decades of research, the exact nature of dark matter remains one of the greatest mysteries in modern physics, with scientists exploring various theories, such as weakly interacting massive particles (WIMPs) and axions, to explain its properties and behavior.



<h2 class="wp-block-heading" id="h-ever-present-force-of-gravity">Ever-present force of gravity</h2>



Gravity is one of the four fundamental forces of nature, alongside <a href="https://www.earth.com/news/strong-magnetic-fields-leave-marks-on-nuclear-matter/" target="_blank" rel="noreferrer noopener">electromagnetism</a>, the strong nuclear force, and the weak nuclear force. It is the force that attracts objects with mass towards each other, and it plays a crucial role in shaping the universe at all scales.



At the Earth's surface, gravity pulls objects towards the center of the planet, giving them weight and keeping them grounded. 



On a larger scale, gravity governs the orbits of planets around the sun, the motion of stars within galaxies, and the formation and evolution of galaxies and galaxy clusters.



According to Albert Einstein's <a href="https://cfa.harvard.edu/research/science-field/einsteins-theory-gravitation" target="_blank" rel="noreferrer noopener">theory of general relativit</a>y, gravity arises from the curvature of space-time caused by the presence of mass and energy. The more massive an object is, the greater its gravitational influence on other objects. 



Despite its ubiquity and importance, gravity remains one of the least understood forces in physics, with ongoing research seeking to reconcile it with the principles of quantum mechanics and to explain phenomena such as dark matter and <a href="https://www.earth.com/news/dark-energy-is-ripping-the-universe-apart-but-we-arent-sure-how/" target="_blank" rel="noreferrer noopener">dark energy</a>.



<h2 class="wp-block-heading" id="h-seeing-gravity-and-dark-matter-in-a-new-light">Seeing gravity and dark matter in a new light</h2>



Taking a fresh perspective, a recent study by <a href="https://www.uah.edu/science/departments/physics/faculty-staff/dr-richard-lieu" target="_blank" rel="noreferrer noopener">Dr. Richard Lieu</a> at The University of Alabama in Huntsville (<a href="https://www.uah.edu/" target="_blank" rel="noreferrer noopener">UAH</a>) hopes to solve the puzzle by adding a new twist to this age-old problem. 



Published in the Monthly Notices of the Royal Astronomical Society, Lieu's paper demonstrates, for the first time, how gravity can exist without mass. 



This radical and thought-provoking research provides an alternative theory that could potentially mitigate the need for dark matter.



"My own inspiration came from my pursuit for another solution to the gravitational field equations of <a href="https://www.earth.com/news/radical-new-theory-finally-unites-gravity-spacetime-and-the-quantum-realm/" target="_blank" rel="noreferrer noopener">general relativity</a>," says Lieu, a distinguished professor of physics and astronomy at UAH. 



"This initiative is in turn driven by my frustration with the status quo, namely the notion of dark matter's existence despite the lack of any direct evidence for a whole century."



<h2 class="wp-block-heading" id="h-topological-defects-may-hold-the-key">Topological defects may hold the key</h2>



Lieu contends that the "excess" gravity necessary to bind a galaxy or cluster together could be due to concentric sets of shell-like topological defects in structures commonly found <a href="https://www.earth.com/news/echo-of-gravitational-waves-heard-for-the-first-time-finally-confirming-their-existence/" target="_blank" rel="noreferrer noopener">throughout the cosmos</a>. 



These defects were most likely created during the early universe when a cosmological phase transition occurred, a physical process where the overall state of matter changes together across the entire universe.



"It is unclear presently what precise form of phase transition in the universe could give rise to topological defects of this sort," Lieu says. 



"Topological effects are very compact regions of space with a very high density of matter, usually in the form of linear structures known as cosmic strings, although 2D structures such as spherical shells are also possible."



<h2 class="wp-block-heading" id="h-massless-gravity-effect-resembles-dark-matter">Massless gravity effect resembles dark matter</h2>



The shells proposed in Lieu's paper consist of a thin inner layer of positive mass and a thin outer layer of negative mass. 



While the total mass of both layers is exactly zero, a star lying on this shell experiences a large gravitational force pulling it towards the center of the shell.



As <a href="https://www.earth.com/news/gravitys-grasp-antimatter-behaves-like-regular-matter/" target="_blank" rel="noreferrer noopener">gravitational force</a> fundamentally involves the warping of space-time itself, it enables all objects to interact with each other, whether they have mass or not. 



Massless photons, for example, have been confirmed to experience gravitational effects from astronomical objects.



"<a href="https://www.earth.com/news/webb-telescope-finds-a-second-lensed-supernova-in-a-distant-galaxy/" target="_blank" rel="noreferrer noopener">Gravitational bending of light</a> by a set of concentric singular shells comprising a galaxy or cluster is due to a ray of light being deflected slightly inwards -- that is, towards the center of the large-scale structure, or the set of shells -- as it passes through one shell," Lieu notes. 



He explains that as light traverses through multiple shells, the cumulative effect results in a measurable deflection that closely resembles the gravitational influence typically attributed to the presence of a significant amount of dark matter, akin to the observed velocities of stellar orbits within galaxies.



<h2 class="wp-block-heading" id="h-role-of-massless-shells-in-galaxy-formation">Role of massless shells in galaxy formation</h2>



The deflection of light and stellar orbital velocities are the only means by which one gauges the strength of the <a href="https://www.earth.com/news/gravity-measured-in-the-quantum-realm-for-the-first-time-ever/" target="_blank" rel="noreferrer noopener">gravitational field</a> in a large-scale structure, be it a galaxy or a cluster of galaxies. 



Lieu's paper contends that the shells it posits are massless, suggesting that there may be no need to perpetuate the seemingly endless search for dark matter.



Questions for future research will likely focus on how a galaxy or cluster is formed by the alignment of these shells, as well as how the evolution of the structures takes place.



"Of course, the availability of a second solution, even if it is highly suggestive, is not by itself sufficient to discredit the dark matter hypothesis -- it could be an interesting mathematical exercise at best," Lieu concludes. 



Lieu emphasizes that his research does not aim to address the issue of structure formation in the universe, and acknowledges that there are still open questions regarding the initial state of the shells and how to definitively confirm or refute their existence through targeted observations. 



Despite these limitations, Lieu asserts that his work represents the first demonstration of the possibility of gravity existing without mass.



<h2 class="wp-block-heading" id="h-dark-matter-vs-massless-gravity-let-the-games-begin">Dark matter vs. Massless gravity: Let the games begin</h2>



In summary, Dr. Richard Lieu's fascinating research challenges the <a href="https://www.earth.com/news/existence-of-dark-matter-confirmed-by-new-study/" target="_blank" rel="noreferrer noopener">century-old notion</a> of dark matter and offers a revolutionary perspective on the nature of gravity. 



By demonstrating how gravity can exist without mass through the concept of massless shells, Lieu's work opens up new avenues for understanding the universe and its fundamental forces. 



While further investigation is necessary to confirm or refute the existence of these massless shells, this study represents a significant leap forward in our comprehension of the cosmos. 



As the scientific community continues to explore the implications of Lieu's findings, we may be on the cusp of a new era in astrophysics, one that reshapes our understanding of the mysterious force that binds galaxies and clusters together.



The full study was published in the journal <a href="https://academic.oup.com/mnras/article/531/1/1630/7673084?login=true" target="_blank" rel="noreferrer noopener">Monthly Notices of the Royal Astronomical Society</a>.



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New theory: Gravity can exist without mass, so dark matter does not exist

For centuries, scientists have grappled with the fundamental forces that...

The familiar patterns of <a href="https://www.earth.com/news/global-warming-is-disrupting-the-seasonal-flow-of-rivers/" target="_blank" rel="noreferrer noopener">streamflow</a> across the Northern Hemisphere are changing due to a decline in snowfall, raising the risk of summer <a href="https://www.earth.com/news/global-drought-crisis-un-warns-of-unprecedented-emergency/" target="_blank" rel="noreferrer noopener">droughts</a>.



Regions like North America's Rocky Mountains, the European Alps, and northern Europe, traditionally covered with snow, are experiencing premature thaws. This shift, driven by <a href="https://www.earth.com/news/global-warming-will-produce-droughts-that-persist-for-years/" target="_blank" rel="noreferrer noopener">global warming</a>, disrupts the expected flow of rivers during the summer.



Meanwhile, in areas accustomed to less snowfall, the onset of seasonal streams is delayed, with warm-season rains starting later in the year and becoming a predominant source of river flow.



Additionally, winter precipitation has decreased, compounding the summer drought risk.



<h2 class="wp-block-heading" id="h-implications-of-changing-streamflows">Implications of changing streamflows</h2>



The research highlights a growing risk of summer droughts. Such conditions are likely to impact several critical areas: water and food security, ecosystem health, and hydropower generation.



Dr. Ross Woods from the <a href="https://www.bristol.ac.uk/engineering/" target="_blank" rel="noreferrer noopener">University of Bristol’s Faculty of Engineering</a> emphasized the broader implications of these findings.



"The way water is distributed through the year is shifting, and this has profound implications not only for ecosystems but also for how we manage food security and respond to natural hazards," explained Dr. Woods.



In some regions, where snowfall significantly contributes to the water cycle, it has been observed that precipitation in a <a href="https://www.earth.com/news/flash-droughts-are-increasing-around-the-world-due-to-warming-climate/" target="_blank" rel="noreferrer noopener">warming climate</a> is less likely to fall as snow. The resulting changes to <a href="https://www.earth.com/news/human-driven-climate-change-is-to-blame-for-sharp-snowpack-declines-since-1980/" target="_blank" rel="noreferrer noopener">snowpacks</a> and the timing of river flows generated by meltwater are noteworthy.



"Initially, there were varied reports about these changes; some regions reported earlier peaks while others saw little to no shift or even later occurrences in the year," said Dr. Woods.



<h2 class="wp-block-heading" id="h-studying-thousands-of-river-basins">Studying thousands of river basins</h2>



The researchers conducted an extensive analysis of climate and river flow data from more than 3,000 river basins in the Northern hemisphere, spanning from 1950 to 2020.



The team assessed changes in the proportion of precipitation falling as snow, the seasonal variations, and the timing of both precipitation and river flow, comparing these elements across two distinct ten-year periods - one with the highest snowfall fraction and the other with the lowest.



"The increased variability from year to year in how water flows through these rivers suggests we're facing more uncertainty moving forward. This makes planning and managing water resources a significant challenge," noted Dr. Woods.



<h2 class="wp-block-heading" id="h-understanding-streamflow-to-combat-summer-drought">Understanding streamflow to combat summer drought</h2>



As the climate continues to warm, the peaks of seasonal streamflows tend to diminish, leading to a more even distribution of river flow throughout the year. The reduction in seasonal variation is primarily due to a decrease in streamflow during the warm seasons, while cold-season flows remain comparatively stable.



"The interannual variability in timing and seasonal shifts during periods of declining <a href="https://www.earth.com/news/lack-of-fresh-snowfall-causes-greenland-to-melt-faster/">snowfall</a> underscores the need for future water management plans to accommodate greater variability," said Dr. Woods.



The research team is now set to delve deeper into the reasons behind consistent reductions in precipitation during the colder seasons of warmer winters, aiming to refine their understanding and improve predictive capabilities for future climate scenarios.



<h2 class="wp-block-heading" id="h-potential-impacts-of-summer-droughts">Potential impacts of summer droughts</h2>



Summer droughts have far-reaching impacts beyond the scope of current research, affecting various sectors and ecosystems. 



One critical area is agriculture. Prolonged droughts can severely reduce crop yields, leading to food shortages and increased prices. This threatens food security, especially in regions heavily dependent on rain-fed agriculture.



The energy sector also feels the effects. Many hydropower plants rely on consistent river flow to generate electricity. Reduced water availability during droughts can limit power production, leading to energy shortages and increased reliance on fossil fuels, which exacerbates climate change.



Ecosystems and biodiversity face significant threats as well. Aquatic habitats suffer when river levels drop, impacting fish and other wildlife. Terrestrial ecosystems, particularly forests, are more prone to wildfires during dry conditions, leading to habitat loss and decreased biodiversity.



Public health can also deteriorate due to water scarcity, as limited water supplies may lead to inadequate sanitation and hygiene. This increases the risk of waterborne diseases. Additionally, the stress on water resources can lead to conflicts over water usage among communities, regions, or even nations.



The research is published in the journal <a href="http://10.1038/s41586-024-07299-y" target="_blank" rel="noreferrer noopener">Nature</a>.



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Growing risk of summer droughts linked to changes in river flow

The familiar patterns of streamflow across the Northern Hemisphere are...

Scientists have recently developed a remarkable equation that accurately describes the flapping frequencies of various flying and diving creatures, including <a href="https://www.earth.com/news/birds-have-adapted-to-human-activities-for-thousands-of-years/" target="_blank" rel="noreferrer noopener">birds</a>, insects, bats, and whales.



This discovery spans species with vastly different sizes, wing shapes, and evolutionary backgrounds.



<h2 class="wp-block-heading" id="h-universal-equation-of-flapping-frequencies">Universal equation of flapping frequencies</h2>



Flying is a complex feat of nature that has evolved independently across multiple animal groups. To optimize <a href="https://www.earth.com/news/insect-flight-is-powered-by-an-extraordinary-structure/" target="_blank" rel="noreferrer noopener">flight</a>, the frequency of wing flaps is ideally aligned with the wing’s natural resonance frequency.



Historically, creating a universal mathematical model for such a diverse range of <a href="https://www.earth.com/news/the-silent-flight-of-owls-is-one-of-natures-great-mysteries/" target="_blank" rel="noreferrer noopener">flying abilities</a> has been challenging.



In a new study, Jens Højgaard Jensen and his team at <a href="https://ruc.dk/en" target="_blank" rel="noreferrer noopener">Roskilde University</a> in Denmark used dimensional analysis to craft an equation that captures the essence of flapping flight.



This formula not only accounts for the flapping frequencies of birds, insects, and bats but also includes the fin movements of diving animals like penguins and whales.



<h2 class="wp-block-heading" id="h-validating-the-universal-flapping-equation">Validating the universal flapping equation</h2>



The researchers validated their model by comparing its predictions with existing data on the <a href="https://www.earth.com/news/amazing-fact-insect-wings-flap-faster-than-their-brain-speed-can-command/" target="_blank" rel="noreferrer noopener">wingbeat</a> frequencies of a variety of species, from bees and dragonflies to bats and hummingbirds.



Their findings reveal a consistent proportionality between the wing or fin-beat frequency and the square root of the animal's body mass divided by its wing area.



This universal equation of flapping frequencies holds true even when extending the research to fin strokes of diving creatures, including penguins and several whale species like the humpback and northern bottlenose.



The model's predictions closely align with observed data across these diverse forms of life.



<h2 class="wp-block-heading" id="h-implications-of-a-universal-flapping-equation">Implications of a universal flapping equation </h2>



The study reveals a surprisingly consistent relationship between body mass, wing area, and <a href="https://www.earth.com/news/what-makes-the-gentoo-penguin-the-worlds-fastest-swimming-bird/" target="_blank" rel="noreferrer noopener">flapping</a> frequency, which persists despite significant physical differences among species.



This constancy is remarkable, especially considering the varied evolutionary histories and body structures of these animals.



Moreover, the researchers estimated that Quetzalcoatlus northropi, an extinct pterosaur and the largest known flying animal, would have flapped its massive 10 meter-square wings at a frequency of about 0.7 hertz. 



This insight into extinct species' movements is a testament to the robustness of the equation.



<h2 class="wp-block-heading" id="h-challenges-and-future-research">Challenges and future research</h2>



Despite these successes, the study faced limitations, particularly in gathering comprehensive data for swimming animals. The team often had to integrate data from multiple sources or estimate certain parameters.



Furthermore, the flapping equation may not apply to extremely small creatures, as the physics of fluid dynamics changes at very small scales. This finding has potential implications for the development of flying nanobots.



<h2 class="wp-block-heading" id="h-a-simple-yet-effective-model">A simple yet effective model</h2>



The simplicity and effectiveness of this universal equation of flapping frequencies have surprised even the physicists behind the study.



"Differing almost a factor of 10,000 in wing/fin-beat frequency, data for 414 animals from the blue whale to mosquitoes fall on the same line," the authors noted. 



Their findings underscore the predictive power of their model across an impressively broad range of species.



<h2 class="wp-block-heading" id="h-exploring-the-principles-of-flapping-frequencies">Exploring the principles of flapping frequencies</h2>



This research not only deepens our understanding of the equations of physical dynamics governing the flapping frequencies in both flight and diving but also highlights the interconnectedness of life forms on Earth.



By revealing consistent patterns across such diverse species, the study invites us to look at wildlife from a new perspective, emphasizing the universal principles that govern natural movement.



<h2 class="wp-block-heading" id="h-significance-of-body-mass-and-wing-area">Significance of body mass and wing area</h2>



In understanding how animals <a href="https://www.earth.com/news/how-do-flying-insects-fight-the-wind-to-reach-food-sources/" target="_blank" rel="noreferrer noopener">fly</a> or swim, body mass and wing area play crucial roles in determining the efficiency and style of movement. These factors influence the energy expenditure and aerodynamic properties of the animal. 



Larger animals typically have more muscle mass, which enables them to generate greater thrust. However, they also need larger wings or fins to support their weight during flight or swimming.



Wing area is vital because it affects the lift generated during flight. A larger wing area allows for greater lift, which is especially important for heavier animals. Conversely, smaller animals with less body mass can afford smaller wings, as their weight requires less lift to remain airborne.



The frequency of wing flaps or fin strokes also ties into these factors. Larger animals, like whales and large birds, tend to have slower, more powerful strokes. In contrast, smaller creatures like insects and small birds flap their wings much more rapidly. This difference in frequency helps maintain the necessary balance of lift and thrust needed for their respective sizes and weights.



In addition to body mass and wing area, other factors such as wing shape, muscle power, and flight style (gliding vs. flapping) also significantly affect how animals move through air or water. For instance, birds with long, narrow wings are optimized for gliding, whereas those with shorter, broader wings excel in flapping flight.



Understanding these relationships helps in various fields, from designing efficient aircraft to developing bio-inspired robotic systems. Researchers continue to explore these dynamics to uncover more about the fascinating mechanics of animal locomotion.



The study is published in the journal <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0303834" target="_blank" rel="noreferrer noopener">PLoS ONE</a>.



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Universal equation predicts the flapping frequency of birds, insects, and even whales

Scientists have recently developed a remarkable equation that accurately describes...

A recent breakthrough in paleontology has shed light on the early evolution of sponges, one of the Earth's oldest known animal groups. Researchers have unearthed a <a href="https://www.earth.com/news/470-million-year-old-animal-fossils-discovered-in-frances-cabrieres-biota/" target="_blank" rel="noreferrer noopener">fossil</a> from the late Ediacaran period, around 550 million years ago, that offers new insights into this ancient lineage.



This finding from the Shibantan Biota in Hubei Province reveals a crown-group sponge, Helicolocellus, which showcases features that are both unique and instructive about the origins of marine life.



<h2 class="wp-block-heading" id="h-mystery-of-missing-sponge-fossils">Mystery of missing sponge fossils</h2>



Traditionally, <a href="https://www.earth.com/news/new-sponges-discovered-in-unexplored-deep-sea-habitats/" target="_blank" rel="noreferrer noopener">sponges</a> are viewed as the most basal and primitive group within the metazoans.



However, despite molecular estimates that suggest sponges appeared around 700 million years ago, concrete fossil evidence from before the Cambrian period (about 539 million years ago) was conspicuously absent.



This 160-million-year gap, often referred to as the "lost years," posed a significant mystery in the evolutionary timeline of sponges.



Two main hypotheses have tried to explain this absence. The first suggests that early sponges had mineralized spicules made of siliceous or calcareous materials, which should have left a fossil record. The lack of such fossils was attributed to potential issues with preservation due to the chemical composition of ancient porewaters.



The second hypothesis posits that the earliest sponges were non-biomineralizing, meaning they lacked hard, mineralized components, making their preservation in the fossil record more challenging.



<h2 class="wp-block-heading" id="h-discovery-of-helicolocellus">Discovery of Helicolocellus</h2>



The discovery of Helicolocellus supports the latter hypothesis. This ancient sponge shows a structure strikingly similar to modern glass sponges, featuring a radially symmetric, conical body and a complex internal architecture including a possible central cavity and inferred excurrent canals.



Its surface is composed of a unique grid pattern, subdivided into progressively smaller boxes, reminiscent of structures seen in some Paleozoic sponges. 



Unlike its later relatives, however, Helicolocellus's grids are made of organic matter, not biomineralized spicules.



<h2 class="wp-block-heading" id="h-scientific-analysis-and-implications">Scientific analysis and implications</h2>



To solidify their findings, the research team conducted a comprehensive phylogenetic analysis using a morphological data matrix that included both extinct and extant animals. 



The results confirm that Helicolocellus belongs to the crown group of sponges, closely related to hexactinellids, or glass sponges. 



This suggests that the evolutionary ancestors of modern sponges might have first constructed their skeletal structures from organic materials before evolving to incorporate siliceous biominerals during the Cambrian period.



<h2 class="wp-block-heading" id="h-connecting-ediacaran-and-cambrian-life">Connecting Ediacaran and Cambrian life</h2>



This discovery not only fills a crucial gap in the <a href="https://www.earth.com/news/tiktaalik-fossil-discovery-sheds-light-on-how-fish-walked-onto-land/" target="_blank" rel="noreferrer noopener">fossil</a> record but also links the enigmatic Ediacara Biota with Cambrian animals, suggesting a continuity between these two major evolutionary stages.



One reviewer aptly noted that Helicolocellus could be considered the "Rosetta Stone" of animal evolution, providing key insights into how modern marine ecosystems began to take shape.



<h2 class="wp-block-heading" id="h-significance-of-fossil-sponges">Significance of fossil sponges</h2>



The discovery of Helicolocellus is a significant milestone in understanding the early evolution of sponges and, more broadly, the origins of animal life. 



It challenges the conventional reliance on biomineralization for fossil preservation and underscores the diversity and complexity of early metazoan life. 



As research continues, each fossil discovery like Helicolocellus adds a piece to the puzzle of our planet's biological heritage, offering a clearer picture of the intricate tapestry of life that has spanned millions of years.



<h2 class="wp-block-heading" id="h-broader-implications">Broader implications</h2>



The discovery influences several broader scientific discussions. For instance, it provides a fresh perspective on the debate about early animal evolution, particularly the development of skeletal structures in ancient marine organisms. 



Helicolocellus's organic grid pattern challenges existing notions about the timeline of biomineralization in sponges and other early animals.



Moreover, this find could spark interest in re-examining other fossil records from the Ediacaran period, potentially revealing more about the diversity and complexity of pre-Cambrian life. 



It might also encourage exploration in less-studied fossil sites worldwide, potentially uncovering more early sponge fossils and offering new insights into early marine ecosystems.



Helicolocellus's discovery could inspire advancements in biomimetic materials. The unique structural features observed in this ancient sponge might lead to innovations in material science, particularly in developing lightweight and durable materials inspired by nature's earliest designs.



Ultimately, the discovery of Helicolocellus not only fills a significant gap in the <a href="https://www.earth.com/news/ugly-fossil-unveils-secrets-of-extinct-cats/" target="_blank" rel="noreferrer noopener">fossil</a> record but also opens new avenues for scientific exploration and innovation.



The study is published in the journal <a href="https://www.nature.com/articles/s41586-024-07520-y" target="_blank" rel="noreferrer noopener">Nature</a>.



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550-million-year-old fossil sponge discovered in China

A recent breakthrough in paleontology has shed light on the...

An international team of scientists, with significant contributions from the University of Hawaii Institute for Astronomy (<a href="https://www.ifa.hawaii.edu/" target="_blank" rel="noreferrer noopener">IfA</a>), has unveiled a new catalog of 120 confirmed and six candidate exoplanets.



<h2 class="wp-block-heading" id="h-telescopes-involved-in-the-discovery">Telescopes involved in the discovery</h2>



These <a href="https://www.earth.com/news/volcanic-exoplanet-glows-with-red-hot-molten-lava/" target="_blank" rel="noreferrer noopener">celestial</a> discoveries were made using NASA’s Transiting Exoplanet Survey Satellite (TESS) and the W. M. Keck Observatory on Maunakea, Hawaii.



<h3 class="wp-block-heading" id="h-transiting-exoplanet-survey-satellite-tess">Transiting Exoplanet Survey Satellite (TESS)</h3>



NASA's Transiting Exoplanet Survey Satellite (TESS) was launched in April 2018. Its primary mission is to search for exoplanets - planets outside our solar system. TESS uses the transit method to detect these planets.



This method involves observing the slight dimming of a star's light when a planet passes in front of it. TESS monitors large swaths of the sky, focusing on bright, nearby stars. This approach allows TESS to discover a diverse array of exoplanets, from Earth-sized rocky worlds to large gas giants.



<h3 class="wp-block-heading" id="h-w-m-keck-observatory">W. M. Keck Observatory</h3>



The W. M. Keck Observatory is home to two of the world's largest optical and infrared telescopes. Each telescope has a 10-meter mirror, which provides exceptional sensitivity and resolution. Established in 1993, the observatory has contributed to numerous discoveries in astronomy. 



The high elevation and stable atmospheric conditions on Maunakea make it an ideal location for observing the universe. Keck Observatory plays a crucial role in follow-up observations of exoplanets discovered by TESS. 



By measuring the radial velocities of stars, Keck helps determine the masses of these <a href="https://www.earth.com/news/exoplanet-found-in-the-habitable-zone-of-a-binary-star-system/" target="_blank" rel="noreferrer noopener">planets</a>, providing vital information about their composition and potential habitability. Together, TESS and Keck Observatory form a powerful partnership in the search for and study of exoplanets.



<h2 class="wp-block-heading" id="h-detailed-database-for-studying-exoplanets">Detailed database for studying exoplanets</h2>



The TESS-Keck Survey's Mass Catalog offers astronomers a detailed database to study the latest worlds found by TESS. 



This new resource paves the way for in-depth exploration of these exoplanets' properties and environments, especially those that might <a href="https://www.earth.com/news/scientists-have-identified-85-new-exoplanets-that-could-harbor-life/" target="_blank" rel="noreferrer noopener">harbor life</a>.



The <a href="https://www.hawaii.edu/" target="_blank" rel="noreferrer noopener">University of Hawaii</a> (UH) played a major role in this survey, which includes thousands of radial velocity (RV) observations.



These observations measure a star’s reflex motion caused by an orbiting planet’s gravity, revealing a diverse range of planet types beyond our solar system, from extreme environments to potentially <a href="https://www.earth.com/news/habitable-worlds-new-strategy-to-identify-planets-that-may-host-life/" target="_blank" rel="noreferrer noopener">habitable worlds</a>.



<h2 class="wp-block-heading" id="h-ground-based-observations">Ground-based observations</h2>



“The TESS-Keck Survey demonstrates the very important role of ground-based observations for advancing our understanding of the Universe and, in this case, planets outside our system,” said Dan Huber, an associate astronomer at IfA, co-author of the paper, and co-principal investigator of the TESS-Keck Survey. 



“Space telescopes like TESS can tell us about the sizes of planets, but follow-up observations such as those obtained with Keck provide mass measurements that are required to learn about what these <a href="https://www.earth.com/news/habitable-exoplanet-gliese-12-b-only-40-light-years-away-earth-like-temperatures/" target="_blank" rel="noreferrer noopener">planets</a> are made of.”



Huber, along with IfA astronomer Fei Dai and IfA alumna Ashley Chontos, collaborated with a global team to develop the new exoplanet catalog.



This effort involved analyzing 9,204 RV measurements, with over half taken during 301 observing nights using Keck Observatory’s planet-hunting spectrometer.



The team used the University of California Observatories’ Automated Planet Finder at Lick Observatory for additional radial velocities. Combined, these measurements allowed the calculation of masses for 120 confirmed and six candidate exoplanets.



<h2 class="wp-block-heading" id="h-detailed-database-for-studying-exoplanets-0">Detailed database for studying exoplanets</h2>



The TESS-Keck Survey unveiled a vast diversity of exotic worlds. UH astronomers focused on planets orbiting subgiant stars - future versions of the Sun.



“The Sun will eventually expand into a <a href="https://www.earth.com/image/the-luminous-galaxy-ngc-3783-and-a-blue-giant-star/" target="_blank" rel="noreferrer noopener">giant star</a> after it has fused all hydrogen in its core,” explained Chontos, now a postdoctoral fellow at Princeton. 



“We have some ideas for what might happen to the planets in our solar system, but by directly observing these more evolved systems, we can begin to put together the puzzle pieces and tie the observations to the theory.”



The findings could help predict the fate of our <a href="https://www.earth.com/news/rare-glory-lights-effect-seen-exoplanet-wasp-76b-baffling-astronomers/" target="_blank" rel="noreferrer noopener">planet</a> when the Sun eventually swells and possibly engulfs the Earth.



By studying these evolved systems, researchers can better understand the processes that allow some exoplanets to survive this stage or remain in the process of being engulfed by their expanding stars.



<h2 class="wp-block-heading" id="h-discovering-extreme-worlds">Discovering extreme worlds</h2>



In another notable discovery, Dai and <a href="https://www.caltech.edu" target="_blank" rel="noreferrer noopener">Caltech</a> student Ryan Rubenzahl found the largest rocky planet ever recorded (TOI-1347 b). 



The research suggests that rocky planets like <a href="https://www.earth.com/news/trappist-1-has-seven-earth-like-planets-that-may-support-life/" target="_blank" rel="noreferrer noopener">Earth</a> cannot have masses much more than 10 times that of Earth. Larger planets would likely accrete thick envelopes of lighter gases, becoming more similar to icy or gas giants in our solar system.



The TESS-Keck Survey’s discoveries highlight the critical role of combining space-based observations with ground-based follow-up. 



This approach not only enhances our understanding of exoplanets but also provides insights into the potential for life beyond Earth.



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Exotic worlds: TESS unveils 126 new exoplanets

An international team of scientists, with significant contributions from the...

<a href="https://www.earth.com/news/turn-stress-productive-energy/" target="_blank" rel="noreferrer noopener">Stress</a> is known to negatively impact the human body, but a new study from the <a href="https://ki.se/en" target="_blank" rel="noreferrer noopener">Karolinska Institutet</a> reveals its significant danger to the brain. The research shows that stress can erode cognitive defenses, increasing dementia risk.



<h2 class="wp-block-heading" id="h-stress-is-a-cognitive-thief-nbsp">Stress is a cognitive thief&nbsp;</h2>



The experts explored how daily activities and cognitive health are interconnected. Engaging in mentally stimulating activities, such as education, complex jobs, physical exercise, and social interactions, builds a “cognitive reserve,” which acts as a buffer against dementia symptoms.&nbsp;



However, the researchers add a critical twist: stress can undermine these benefits. High or persistent stress levels act as a cognitive thief, reducing the mental resilience built through these activities.



“Different stress management strategies could be a good complement to existing lifestyle interventions in <a href="https://www.earth.com/news/medical-breakthrough-new-vaccine-may-prevent-alzheimers-disease/" target="_blank" rel="noreferrer noopener">Alzheimer’s</a> prevention,” said lead author Manasa Shanta Yerramalla, a researcher at Karolinska.



<h2 class="wp-block-heading" id="h-life-experiences-build-a-cognitive-reserve-nbsp">Life experiences build a cognitive reserve&nbsp;</h2>



The discovery process began in the late 1980s when researchers noticed that some individuals showed no symptoms of dementia despite having brain changes consistent with Alzheimer’s.&nbsp;



This led to the concept of “cognitive reserve,” suggesting that certain life experiences and behaviors build a mental resilience that protects against cognitive decline.&nbsp;



Each mentally stimulating activity adds a layer of protection, helping maintain normal cognitive function even as Alzheimer's disease progresses.



<h2 class="wp-block-heading" id="h-measuring-the-impact-of-stress">Measuring the impact of stress</h2>



The researchers enrolled 113 participants from a memory clinic to study the relationship between cognitive reserve, cognition, and Alzheimer’s biomarkers.&nbsp;



They also examined the impact of stress, measuring physiological stress (cortisol levels in saliva) and psychological stress (self-reported stress). Cortisol, often called the “stress hormone,” rises under pressure and acts as the body's alarm system.&nbsp;



<h2 class="wp-block-heading" id="h-stress-weakens-our-brain-s-defenses">Stress weakens our brain's defenses </h2>



The study revealed that while greater cognitive reserve improved cognition, higher <a href="https://www.earth.com/news/cortisol-indicate-stressed/" target="_blank" rel="noreferrer noopener">cortisol</a> levels weakened this beneficial relationship, indicating that stress erodes the protective layers of the mental fortress.



This discovery suggests that stress-reducing techniques like mindfulness exercises and meditation, which lower cortisol levels, could be powerful additions to existing lifestyle interventions. Building cognitive reserve through mental activities and managing stress could maintain brain defenses.



“These results might have clinical implications as an expanding body of research suggests that mindfulness exercises and meditation may reduce cortisol levels and improve cognition,” Yerramalla said.



<h2 class="wp-block-heading" id="h-connection-between-sleep-and-cognitive-reserve-nbsp">Connection between sleep and cognitive reserve&nbsp;</h2>



The researchers also considered the impact of stress on <a href="https://www.earth.com/news/getting-high-quality-sleep-helps-prevent-depression-and-anxiety/" target="_blank" rel="noreferrer noopener">sleep</a>, which affects cognition. Although the study factored in sleep medications, more research is needed to understand how poor sleep damages cognitive reserve.



The study opens new avenues for Alzheimer’s prevention by integrating stress management with lifestyle interventions. Understanding how stress affects cognition can lead to better strategies for maintaining cognitive health and preventing dementia.&nbsp;



The scientists plan to continue studying the association between stress, sleep disorders, and cognitive reserve in memory clinic patients to develop effective interventions for Alzheimer's prevention.



<h2 class="wp-block-heading" id="h-impacts-of-stress-on-the-brain">Impacts of stress on the brain</h2>



Stress can significantly impact the brain, affecting both its structure and function in multiple ways.&nbsp;



<h3 class="wp-block-heading" id="h-brain-shrinkage-nbsp">Brain shrinkage&nbsp;</h3>



<a href="https://www.earth.com/news/chronic-stress-causes-the-brain-to-crave-comfort-food/" target="_blank" rel="noreferrer noopener">Chronic stress</a> can lead to the shrinkage of the hippocampus, the part of the brain crucial for memory and learning, while also enlarging the amygdala, which can make the brain more receptive to stress.&nbsp;



This change not only affects memory but also increases emotional reactions and anxiety.



<h3 class="wp-block-heading" id="h-neurochemical-effects">Neurochemical effects</h3>



Neurochemically, stress elevates levels of the hormone cortisol, which can disrupt synapse regulation, leading to a decrease in the brain's ability to process information and cope with stress in the future.&nbsp;



It also hampers the production of new neurons and can contribute to mental health disorders like depression and anxiety over time.



<h3 class="wp-block-heading" id="h-brain-connectivity-nbsp">Brain connectivity&nbsp;</h3>



Furthermore, stress affects the brain’s connectivity; it can weaken the connections between neurons in areas responsible for decision making and self-control, making it more difficult to make rational decisions and manage impulses.&nbsp;



This condition underscores the importance of managing stress through strategies such as mindfulness, exercise, and adequate sleep, which can help mitigate these negative effects on the brain.



The study is published in <a href="https://alz-journals.onlinelibrary.wiley.com/doi/epdf/10.1002/alz.13866" target="_blank" rel="noreferrer noopener">Alzheimer's &amp; Dementia: The Journal of the Alzheimer’s Association</a>,&nbsp;



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Stress ‘eats away’ our brain’s cognitive defenses

Stress is known to negatively impact the human body, but...

The southern cassowary, with its velociraptor-like legs and neon blue neck, stands as a modern-day dinosaur in the rainforests of northeast Australia. Fiercely territorial, these birds hiss and rumble when threatened. 



They have an imposing figure, standing five feet tall and weighing up to 165 pounds. "It's a modern-day dinosaur," said Peter Rowles, president of a community group dedicated to protecting these endangered <a href="https://www.earth.com/news/renewable-energy-is-the-latest-threat-to-bird-populations/" target="_blank" rel="noreferrer noopener">birds</a>.



<h2 class="wp-block-heading" id="h-keystone-species-southern-cassowary">Keystone species: Southern cassowary</h2>



Cassowaries play a vital role in maintaining biodiversity in the rainforests of northeast Australia. One of their most important functions is seed dispersal. These birds consume a variety of fruits, some of which have seeds too large to be dispersed by other animals. 



After eating the fruits, cassowaries travel long distances, excreting the seeds in different locations. This process helps maintain plant diversity and forest structure, as the seeds have a better chance of germinating and growing into new plants far from the parent tree.



<h2 class="wp-block-heading" id="h-collapse-of-ecological-networks">Collapse of ecological networks </h2>



If cassowaries go extinct, the rainforests will suffer significantly. Without these natural gardeners, many plant species that rely on cassowaries for seed dispersal would struggle to reproduce. 



This decline in plant diversity would impact other animals that depend on these plants for food and shelter. Over time, the entire ecosystem could degrade, leading to a loss of biodiversity and the collapse of ecological networks.



The Australian government lists the southern cassowary as <a href="https://www.earth.com/earthpedia-articles/the-12-endangered-birds-most-at-risk-of-extinction/" target="_blank" rel="noreferrer noopener">endangered</a>, with an estimated 4,500 remaining in the wild. These flightless birds are native to Australia, New Guinea, and some Pacific islands. 



<h2 class="wp-block-heading" id="h-threats-a-hostile-environment">Threats: A hostile environment</h2>



Studies show that their population has declined due to <a href="https://www.earth.com/news/urbanization-is-a-threat-to-78-of-the-worlds-bird-species/" target="_blank" rel="noreferrer noopener">habitat loss</a>, car strikes, dog attacks, and climate change. Hence, conservation efforts are crucial to prevent their extinction and protect the delicate balance of their rainforest habitat.



"Cassowaries are not aggressive when they're treated well," said Rowles, noting that few recorded deaths have been caused by the species.



<h2 class="wp-block-heading" id="h-southern-cassowary-attacks">Southern cassowary attacks</h2>



There are a few notable incidents related to cassowary attacks. In 1926, a young Australian boy tragically lost his life following an encounter with a cassowary. The boy had chased the bird, prompting a defensive response. The cassowary, feeling threatened, used its powerful legs and razor-sharp talons to strike back.



One of the talons severed the boy's jugular vein, leading to his death. This incident serves as a reminder of the potential danger posed by these large, territorial birds when they feel cornered or threatened.



Another notable incident occurred in 2019 in Florida, involving a man who kept a cassowary as a pet. The man fell on his property, and the cassowary attacked him. 



The bird’s sharp talons inflicted fatal injuries, leading to the man's death. This tragic event highlights the risks of keeping wild and potentially dangerous animals in domestic settings.



<h2 class="wp-block-heading" id="h-protecting-the-dinosaur-bird">Protecting the dinosaur bird</h2>



Efforts to save cassowaries involve various strategies. Rowles' group runs a cassowary hospital for injured <a href="https://www.earth.com/news/bird-population-north-america-dramatic-decline-lost-3-billion-birds/" target="_blank" rel="noreferrer noopener">birds</a>, redesigns roads to protect native habitats, and installs signs urging drivers to slow down. 



"We thought if we could save cassowaries, we also could save enough habitat to keep a lot of other species alive," said Rowles.



The World Wide Fund for Nature (<a href="https://www.worldwildlife.org" target="_blank" rel="noreferrer noopener">WWF</a>) warns that Australia's extinction rate will likely increase. "There is so much that has to be done and resources are not available to have a significant impact," said Darren Grover, WWF Australia's acting chief conservation officer.



"We're looking at around 2,000 species on the Australian government's threatened species list and more and more species are added to that list yearly."



<h2 class="wp-block-heading" id="h-national-recovery-plan">National recovery plan</h2>



The Australian government has a national recovery plan to save the iconic cassowary bird. This plan involves collaboration with Indigenous and conservation groups. Much of the country's conservation efforts focus on protecting keystone species, a strategy developed by zoologists in the 1960s. 



"This is the best approach when resources are limited, as it provides flow-on effects to other animals in that habitat," said Grover.



<h2 class="wp-block-heading" id="h-the-intricate-web-of-life">The intricate web of life</h2>



Cassowaries are vital to their ecosystem, yet they are naturally cranky and powerful. "Cassowaries are amazing species and whenever you get to see them in the wild is fantastic," said Grover. "But be careful because they are naturally cranky birds, they are big and powerful and we need to give them some space."



The fight to save the southern cassowary reflects broader challenges in conservation. With limited resources and growing threats, efforts must intensify to protect these modern-day dinosaurs. 



As Rowles and Grover highlight, saving cassowaries means preserving the intricate web of life in Australia's rainforests. The extinction of this keystone species would signify a profound loss, not just for the ecosystem but for the planet's biodiversity.



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Dinosaur bird may soon go extinct

The southern cassowary, with its velociraptor-like legs and neon blue...

Earth,Continents,Painted,On,Face,Skin,,Concept,Save,The,Planet.

Have you ever wondered how many humans have lived and died on planet Earth throughout history? This question has captivated the minds of demographers, researchers, and curious individuals alike. 



Estimating the total number of humans who have ever existed is a complex task that requires making educated guesses about population sizes, birth rates, and mortality rates over the vast expanse of human history.



The most widely cited estimate, provided by the Population Reference Bureau (<a href="https://www.prb.org/" target="_blank" rel="noreferrer noopener">PRB</a>), suggests that approximately 108 billion people have called Earth home. Let's explore the methodology and reasoning behind this fascinating figure.



<h2 class="wp-block-heading" id="h-setting-the-stage-dawn-of-modern-humans">Setting the stage: Dawn of modern humans</h2>



To begin our journey, we need to establish a starting point for when modern humans (Homo sapiens) first appeared. Most anthropologists agree that modern Homo sapiens emerged around <a href="https://www.earth.com/news/earliest-human-footprints-ever-found-are-believed-to-be-300000-years-old/" target="_blank" rel="noreferrer noopener">300,000 years ago</a>. 



However, for the purposes of demographic estimation, researchers often consider a more conservative starting point of around 50,000 years ago, when humans began to exhibit behaviorally modern traits, such as creating art and using <a href="https://www.earth.com/news/stone-age-humans-used-tools-to-make-timber-for-woodworking/" target="_blank" rel="noreferrer noopener">tools</a>.



The <a href="https://www.earth.com/news/neanderthals-and-humans-lived-side-by-side-45000-years-ago/" target="_blank" rel="noreferrer noopener">Upper Paleolithic</a> period, which began around 40,000 years ago, witnessed the emergence of increasingly complex tools and technologies. The advancements made by these "modern humans" included the use of bone needles, fishhooks, harpoons, woodworking, and <a href="https://www.earth.com/news/neanderthals-glue-created-and-used-underestimated-intelligence/" target="_blank" rel="noreferrer noopener">glue</a>. 



These sophisticated tools allowed for more efficient hunting, fishing, and the creation of intricate clothing and other objects. 



Moreover, the Upper Paleolithic era is notable for the earliest known examples of artistic expression, such as <a href="https://www.earth.com/news/spanish-cave-was-used-for-art-and-burials-for-50000-years/" target="_blank" rel="noreferrer noopener">cave paintings</a> and carved figurines, which provide a glimpse into the cognitive and creative abilities of our ancestors.



<h2 class="wp-block-heading" id="h-what-we-know-about-early-populations">What we know about early populations</h2>



Estimating the population size of early humans is a challenging task due to the lack of written records and limited archaeological evidence. Researchers rely on various indirect methods to make informed guesses. 



They examine the carrying capacity of ancient environments and study genetic diversity to gain insights into early population dynamics.



During the majority of human history, our ancestors lived as hunter-gatherers. Estimates suggest that the global population during this period was relatively small, likely ranging from 1 to 10 million individuals. 



Population growth was slow due to high mortality rates and limited resources. However, around 10,000 BCE, the <a href="https://www.earth.com/news/stone-tool-discovery-challenges-entire-theory-of-human-evolution/" target="_blank" rel="noreferrer noopener">agricultural revolution</a> significantly changed the course of human society and population dynamics. 



With the ability to produce surplus food, human populations began to grow more rapidly. By the year 1 CE, estimates place the global population at approximately 300 million.



<h2 class="wp-block-heading" id="h-estimating-populations-and-birth-rates">Estimating populations and birth rates</h2>



Understanding historical birth rates is crucial in estimating the total number of humans who have ever lived. Birth rates are influenced by a multitude of factors, including cultural practices, economic conditions, and mortality rates.



In pre-industrial societies, birth rates were high, often exceeding 40 births per 1,000 individuals annually. However, high infant and child mortality rates meant that many of these births did not result in long-term population growth. 



The <a href="https://www.earth.com/news/psychological-impact-industrial-revolution/" target="_blank" rel="noreferrer noopener">industrial revolution</a> brought about significant changes, including improvements in medicine, sanitation, and food production. These advancements led to lower mortality rates and sustained population growth. 



As a result, the global population grew from about 1 billion in 1800 to over 7 billion in the early 21st century.



<h2 class="wp-block-heading" id="h-historical-periods-of-humans-on-earth">Historical periods of humans on Earth</h2>



To arrive at the total number of humans who have ever lived, demographers follow a systematic approach. They divide human history into different periods based on major technological, cultural, and societal changes. 



Each period has different population sizes and birth rates. Researchers estimate the average population size for each period and calculate the total number of births by multiplying the average population size by the birth rate and the length of the period. 



This calculation accounts for the fact that populations were not static and grew over time. Finally, researchers sum the number of births across all periods to arrive at the grand total.



<h2 class="wp-block-heading" id="h-crunching-the-numbers">Crunching the numbers</h2>



Let's consider a simplified example to illustrate this process. For the <a href="https://www.earth.com/news/our-hunter-gatherer-ancestors-did-much-more-gathering-than-hunting/" target="_blank" rel="noreferrer noopener">hunter-gatherer</a> period (50,000 BCE - 10,000 BCE), with an average population of 5 million, a birth rate of 40 per 1,000 annually, and a period length of 40,000 years, the estimated births would be 8 billion. 



Similarly, for the agricultural revolution period (10,000 BCE - 1 CE), with an average population of 100 million, a birth rate of 30 per 1,000 annually, and a period length of 10,000 years, the estimated births would be 30 billion. 



For the modern era (1 CE - 2024 CE), with a weighted average population of 1 billion, a birth rate of 20 per 1,000 annually, and a period length of 2,024 years, the estimated births would be approximately 40.48 billion.



Summing these estimates gives a total of around 78.48 billion births. Adjustments and more refined estimates, such as those from the PRB, typically result in a widely cited figure: approximately 108 billion people have lived, walked, and died on Earth since the dawn of humanity.



<h2 class="wp-block-heading" id="h-earth-has-been-home-to-108-billion-humans">Earth has been home to 108 billion humans</h2>



Estimating the total number of humans who have ever lived is a testament to the complex interplay of demographic factors, historical data, and educated assumptions. 



While the figure of 108 billion is an estimate, it provides a captivating glimpse into the immense scale of human existence on Earth. 



This number reminds us of the long and diverse <a href="https://www.earth.com/news/modern-humans-almost-went-extinct-as-population-declined-to-1280-individuals/" target="_blank" rel="noreferrer noopener">history of our species</a> and the countless lives that have shaped the human story.



In summary, as we ponder this staggering figure, we are reminded of the shared experiences, struggles, and triumphs that have defined human existence throughout the ages. 



Each individual life, whether lived in the distant past or in the present, has contributed to the tapestry of humanity. 



The next time you find yourself wondering about the vastness of human history, remember that you are part of a lineage that spans over 100 billion lives, each leaving its mark on the world we inhabit today.



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How many humans have lived and died on Earth? It's a complex question and a very big number

Have you ever wondered how many humans have lived and...

Our understanding of the Milky Way might be facing a cosmic shakeup. A recent study by researchers from the <a href="https://www.rpi.edu" target="_blank" rel="noreferrer noopener">Rensselaer Polytechnic Institute</a> suggests that our Milky Way experienced a major collision much more recently than previously thought.



This discovery challenges long-held beliefs and offers a fresh perspective on the Milky Way’s formation and evolution.



<h2 class="wp-block-heading" id="h-mystery-of-milky-way-s-collision">Mystery of Milky Way's collision</h2>



Scientists have believed for years that the Milky Way’s last significant merger happened between eight and eleven billion years ago. 



Known as the Gaia-Sausage/Enceladus (GSE) event, this collision was thought to have shaped much of the galaxy we see today.



However, new research reveals that a significant merger might have occurred just one to two billion years ago. <a href="https://youtu.be/rySJiLjXr2I" target="_blank" rel="noreferrer noopener">This recent collision</a> would place it well after the formation of Earth.



<h2 class="wp-block-heading" id="h-wrinkles-in-the-milky-way-due-to-collision">"Wrinkles" in the Milky Way due to collision</h2>



Researchers Heidi Jo Newberg and Tom Donlon spearheaded this study, focusing on the "wrinkles" in <a href="https://www.earth.com/news/uma3-u1-faintest-star-system-found-orbiting-milky-way-galaxy/" target="_blank" rel="noreferrer noopener">our galaxy</a>. These wrinkles form when other galaxies smash into the Milky Way. 



“We get wrinklier as we age, but our work reveals that the opposite is true for the Milky Way. It’s a sort of cosmic Benjamin Button, getting less wrinkly over time,” noted Donlon.



By studying how these wrinkles dissipate, the team traced the timeline of the last big collision.



<h2 class="wp-block-heading" id="h-pinpointing-the-milky-way-s-last-merger">Pinpointing the Milky Way's last merger</h2>



The study's innovative approach used a semi-analytical model to relate the number of “caustics” (wrinkles in the phase-space distribution of <a href="https://www.earth.com/news/newly-discovered-stars-milky-way-are-old-as-universe/" target="_blank" rel="noreferrer noopener">stars</a>) to the time since a merger event. 



Analyzing data from the Gaia space observatory, the researchers identified several caustics in the local stellar halo. They compared these findings with a state-of-the-art cosmological simulation, part of the FIRE-2 Latte suite, to determine the timeline of the collision.



“For the wrinkles of <a href="https://www.earth.com/news/stars-at-the-edge-of-our-milky-way-galaxy-travel-more-slowly/" target="_blank" rel="noreferrer noopener">stars</a> to be as obvious as they appear in Gaia data, they must have joined us no less than three billion years ago – at least five billion years later than was previously thought,” said Newberg.



<h2 class="wp-block-heading" id="h-new-metric-for-milky-way-collision">New metric for Milky Way collision</h2>



The team introduced a novel metric called “causticality,” which measures the unevenness in the phase-space distribution of stars. 



A high causticality value indicates a more recent collision, where the stars have not yet fully phase-mixed. Comparing their observations with simulated data, the researchers found a match at a timeline roughly one to two billion years ago.



The widely accepted GSE scenario, suggesting a merger eight to eleven billion years ago, contrasts sharply with these new findings. 



The observed high causticality in the Gaia data points to a much more recent merger. This discrepancy raises questions about the previously understood formation history of our galaxy.



<h2 class="wp-block-heading" id="h-limitations-and-challenges">Limitations and challenges</h2>



Despite the compelling evidence, the study acknowledges several limitations. One key challenge is the reliance on a single cosmological simulation, which may not capture all of the complexities of the Milky Way’s history.



Additionally, the observed data is limited to the local stellar halo within 16,000 light-years of the Sun. The phase-space distribution of stars at larger distances could potentially reveal a different picture.



Moreover, the up-sampling process used to increase the resolution of the simulated data could introduce biases or underestimations in the degree of phase-mixing.



<h2 class="wp-block-heading" id="h-formation-of-the-milky-way">Formation of the Milky Way</h2>



If confirmed, these findings could significantly impact our understanding of the Milky Way’s formation and the role of mergers in shaping galaxies. 



The study also provides a compelling alternative to the GSE scenario, which has faced increasing scrutiny. Some researchers argue that the chemical and kinematic signatures attributed to the GSE could be explained by other processes, such as secular evolution or multiple smaller mergers.



“Through this study, Doctors Newberg and Donlon have made a startling discovery about the history of the Milky Way galaxy,” noted Dr. Curt Breneman, dean of Rensselaer’s <a href="https://science.rpi.edu" target="_blank" rel="noreferrer noopener">School of Science</a>.



<h2 class="wp-block-heading" id="h-the-milky-way-s-collision-history">The Milky Way's collision history </h2>



The study opens a new chapter in our understanding of the Milky Way and its collision history. The possibility of a significant collision occurring just one to two billion years ago reshapes our perspective on galactic evolution.



As researchers continue to explore the cosmos, we can expect more surprising revelations that challenge our understanding of the universe and our place within it.



In the grand timeline of the universe, a few billion years might seem like a blink of an eye. Yet, for us on Earth, these discoveries provide a profound connection to the vast, <a href="https://www.earth.com/news/milky-way-galaxy-is-surrounded-by-massive-magnetic-fields/" target="_blank" rel="noreferrer noopener">dynamic galaxy</a> we call home.



The study is published in the <a href="https://academic.oup.com/mnras/article/531/1/1422/7675507?login=false" target="_blank" rel="noreferrer noopener">Monthly Notices of the Royal Astronomical Society</a>.



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Milky Way collision may change everything we know about our galaxy

Our understanding of the Milky Way might be facing a...

Each spring, as the warming Arctic sun pierces the long winter darkness, a flurry of life emerges, including the awakening of giant <a href="https://www.earth.com/news/viruses-influence-methane-production-across-various-ecosystems/" target="_blank" rel="noreferrer noopener">viruses</a>. Polar bears leave their dens, Arctic terns return from their migrations, and musk oxen traverse northward.



Alongside these familiar sights, a less visible but equally significant awakening occurs on the Greenland ice sheet. 



As the ice starts to melt, dark patches begin to appear, a phenomenon caused by blooming algae. These algae absorb sunlight, accelerating the ice melt and contributing to <a href="https://www.earth.com/news/highest-points-of-greenland-are-now-affected-by-global-warming/" target="_blank" rel="noreferrer noopener">global warming</a>.



<h2 class="wp-block-heading" id="h-giant-viruses-on-ice">Giant viruses on ice</h2>



In this bleak scenario of global warming, a ray of hope shines through in the form of an unexpected ally: giant viruses.



Postdoctoral researcher Laura Perini and her team at the Department of Environmental Science at <a href="https://envs.au.dk/en/" target="_blank" rel="noreferrer noopener">Aarhus University</a> have made a groundbreaking discovery.



Nestled within the icy expanse, where algae proliferate, giant viruses lie in wait. 



Unlike their microscopic counterparts, these viruses are formidable in size, comparable to bacteria, and could potentially serve as natural regulators of algae growth.



<h2 class="wp-block-heading" id="h-giants-among-microbes">Giants among microbes</h2>



Giant viruses, first identified in 1981, defy the typical characteristics of their kin. Measuring about 2.5 micrometers, they are not just physically larger; their genomes are also expansive, containing millions of genetic letters.



This allows them a level of autonomy uncommon among <a href="https://www.earth.com/news/giant-viruses-found-in-yellowstones-hot-springs-are-1-5-billion-years-old/" target="_blank" rel="noreferrer noopener">viruses</a>, enabling them to replicate and transcribe DNA without a host's cellular machinery.



Such capabilities make them fascinating subjects of study and potentially crucial players in ecological balance.



<h2 class="wp-block-heading" id="h-viruses-in-the-warming-world">Viruses in the warming world</h2>



This discovery on the <a href="https://www.earth.com/news/shock-discovery-greenland-ice-sheet-is-teeming-with-microorganisms/" target="_blank" rel="noreferrer noopener">Greenland ice sheet</a> marks a significant first. "We analyzed samples from various forms of ice and found active giant viruses in areas dominated by pigmented microalgae," noted Perini.



This revelation sheds light on a vibrant, albeit microscopic, ecosystem that thrives in conditions previously thought to be barren.



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2024/06/greenland-ice_covered-viruses_blackened-algae_credit-Shunan-Feng_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2024/06/greenland-ice_covered-viruses_blackened-algae_credit-Shunan-Feng_1s.jpg" alt="Algae blackens the Greenland ice. Credit: Laura Perini" class="wp-image-1936070"/></a><figcaption class="wp-element-caption">Algae blackens the Greenland ice. Credit: Laura Perini</figcaption></figure>



The ecosystem includes bacteria, fungi, and protists - all centered around the algae, with giant viruses perhaps playing a pivotal role in moderating <a href="https://www.earth.com/news/toxic-algal-blooms-will-become-more-frequent-off-the-u-s-west-coast/" target="_blank" rel="noreferrer noopener">algal blooms</a>.



<h2 class="wp-block-heading" id="h-presence-of-mrna">Presence of mRNA</h2>



Despite their size, these viruses elude the naked eye and even conventional microscopes. 



"Our discovery was made by analyzing DNA from collected samples. We sifted through massive datasets to find markers indicative of giant viruses," said Perini.



The presence of mRNA, which decays rapidly unless actively produced by living organisms, further confirmed the activity of these viruses on the ice.



<h2 class="wp-block-heading" id="h-uncertain-role-of-giant-viruses">Uncertain role of giant viruses</h2>



While the potential of these giant viruses to control algae and mitigate ice melt from global warming is promising, much remains unknown.



"Their exact hosts and mechanisms are still unclear. Some may target protists, others the algae directly," noted Perini. Her ongoing research aims to delve deeper into these interactions, with more findings expected to be published later in the year.



<h2 class="wp-block-heading" id="h-giant-viruses-and-global-warming">Giant viruses and global warming</h2>



The study of these giant viruses not only broadens our understanding of viral biology but also opens new avenues in environmental science. 



By exploring these organisms further, scientists like Perini hope to unlock natural solutions to some of the challenges posed by <a href="https://www.earth.com/news/climate-change-is-unleashing-ancient-zombie-viruses/">climate change</a>.



As the Arctic continues to evolve under the pressures of global warming, the role of these viruses could be more significant than ever.



The study represents a crucial step toward understanding the complex interplay of life in one of Earth's most extreme environments.



<h2 class="wp-block-heading" id="h-other-critical-roles-of-giant-viruses">Other critical roles of giant viruses</h2>



Beyond regulating algae on Greenland ice, giant viruses play several critical roles. Their large genomes allow them to perform complex functions, often independent of host cells, which sets them apart from typical viruses. 



In <a href="https://www.earth.com/news/ocean-based-viruses-discovered-that-trap-carbon-and-combat-climate-change/" target="_blank" rel="noreferrer noopener">marine environments</a>, they can control the population of harmful algal blooms, protecting marine life and fisheries. Giant viruses also influence microbial diversity and nutrient cycles, crucial for ecosystem health.



In biomedical research, their unique genetic makeup provides insights into virus evolution and the origins of life. Studying giant viruses can reveal new aspects of gene regulation and viral replication, potentially leading to breakthroughs in antiviral therapies. 



Additionally, these viruses might help in biotechnology, such as gene editing and synthetic biology, due to their large and versatile genomes.



Overall, giant viruses hold promise in various fields, from environmental science to medical research, offering new tools and perspectives for addressing global challenges.



The study is published in the journal <a href="https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-024-01796-y" target="_blank" rel="noreferrer noopener">Microbiome</a>.



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Giant viruses found on Arctic ice may help fight global warming

Each spring, as the warming Arctic sun pierces the long...

This,Is,A,3d,Illustration,Of,Three,Merging,Supermassive,Black

In the vast expanse of the cosmos, there is much more than meets the eye. For every kilogram of <a href="https://www.earth.com/news/visible-matter-dark-matter-evolved-together-big-bang/" target="_blank" rel="noreferrer noopener">visible matter</a> in the universe, from the computer on your desk to the <a href="https://www.earth.com/news/ancient-galaxies-formed-from-the-earliest-elements-in-the-universe/" target="_blank" rel="noreferrer noopener">distant stars and galaxies</a>, there are 5 kilograms of invisible "dark matter" that permeate our surroundings. 



This enigmatic dark matter <a href="https://www.earth.com/news/dark-matter-may-reveal-the-origin-of-magnetic-fields/" target="_blank" rel="noreferrer noopener">evades direct observation</a> yet exerts its invisible pull on the visible objects around us.



<h2 class="wp-block-heading" id="h-stephen-hawking-and-primordial-black-holes">Stephen Hawking and primordial black holes</h2>



Fifty years ago, renowned physicist <a href="https://www.cam.ac.uk/stephenhawking" target="_blank" rel="noreferrer noopener">Stephen Hawking</a> proposed a fascinating idea about the nature of dark matter. He suggested that it might consist of a population of black holes that formed in the early stages of the universe, mere moments after the Big Bang. 



These "primordial" black holes would not have been the colossal entities we detect today, but rather microscopic regions of ultradense matter. 



According to Hawking's theory, these primordial black holes would have formed in the first quintillionth of a second <a href="https://www.earth.com/news/visible-matter-dark-matter-evolved-together-big-bang/">following the</a><a href="https://www.earth.com/news/visible-matter-dark-matter-evolved-together-big-bang/" target="_blank" rel="noreferrer noopener"> </a><a href="https://www.earth.com/news/visible-matter-dark-matter-evolved-together-big-bang/">Big Bang</a>, collapsed, and scattered across the cosmos, influencing the surrounding space-time in ways that could explain the dark matter we observe today.



<h2 class="wp-block-heading" id="h-super-charged-black-holes">Super-charged black holes</h2>



Now, physicists from the Massachusetts Institute of Technology (<a href="https://www.mit.edu" target="_blank" rel="noreferrer noopener">MIT</a>) have made a mind-bending discovery that sheds new light on Hawking's idea. 



David Kaiser, the Germeshausen Professor of the History of Science and professor of physics at MIT, and his graduate student Elba Alonso-Monsalve, found that the primordial process described by Hawking would have also produced some unexpected companions: even smaller black holes with unprecedented amounts of a nuclear-physics property known as "color charge."



These smallest, "super-charged" black holes would have been an <a href="https://www.earth.com/news/dark-matter-does-not-exist-universe-27-billion-years-old-study/" target="_blank" rel="noreferrer noopener">entirely new state</a> of matter, likely evaporating a fraction of a second after their formation. 



Despite their brief existence, they could have influenced a crucial cosmological transition: the time when the first <a href="https://www.earth.com/news/strong-magnetic-fields-leave-marks-on-nuclear-matter/" target="_blank" rel="noreferrer noopener">atomic nuclei</a> were forged.



"Even though these short-lived, exotic creatures are not around today, they could have affected cosmic history in ways that could show up in subtle signals today," explains Kaiser. "Within the idea that all dark matter could be <a href="https://www.earth.com/news/existence-of-dark-matter-confirmed-by-new-study/" target="_blank" rel="noreferrer noopener">accounted for by black holes</a>, this gives us new things to look for."



<h2 class="wp-block-heading" id="h-ultradense-matter-in-the-early-universe">Ultradense matter in the early universe</h2>



Unlike the black holes we know and detect today, which are the product of <a href="https://www.earth.com/news/star-collapse-black-hole-instead-of-supernova-vanish-from-sky/" target="_blank" rel="noreferrer noopener">stellar collapse</a>, primordial black holes are thought to have formed in a time before stars existed. 



In the early universe, before even the basic elements had formed, pockets of ultradense, primordial matter could have accumulated and collapsed to form microscopic black holes. 



These black holes could have been so dense as to squeeze the mass of an asteroid into a region as small as a single atom. 



The gravitational pull from these tiny, invisible objects scattered throughout the universe could explain the dark matter that <a href="https://www.earth.com/news/neutron-stars-may-hold-the-key-to-understanding-dark-matter/" target="_blank" rel="noreferrer noopener">we can't see today</a>.



<h2 class="wp-block-heading" id="h-very-fleeting-existence">Very fleeting existence</h2>



Kaiser and Alonso-Monsalve set out to investigate the composition of these primordial black holes. They looked at existing theories for the likely distribution of black hole masses as they were first forming in the <a href="https://www.earth.com/news/cosmic-lighthouses-emanated-earliest-starlight-universe/" target="_blank" rel="noreferrer noopener">early universe</a>.



"Our realization was, there's a direct correlation between when a primordial black hole forms and what mass it forms with," says Alonso-Monsalve. "And that window of time is absurdly early."



The researchers calculated that primordial black holes must have formed within the first quintillionth of a second <a href="https://www.earth.com/news/black-holes-shaped-the-universe-before-galaxies-existed/" target="_blank" rel="noreferrer noopener">following the Big Bang</a>. 



This brief flash of time would have produced "typical" microscopic black holes with masses ranging from an asteroid to an atom. 



It would have also yielded a small fraction of exponentially smaller black holes, with the mass of a rhino and a size much smaller than a single proton.



<h2 class="wp-block-heading" id="h-understanding-quantum-chromodynamics-qcd">Understanding quantum chromodynamics (QCD)</h2>



To determine the composition of these primordial black holes, Kaiser and Alonso-Monsalve turned to studies exploring the composition of the <a href="https://www.earth.com/news/webb-telescope-discovers-what-powered-the-reionization-of-the-universe/" target="_blank" rel="noreferrer noopener">early universe</a>, specifically focusing on the theory of quantum chromodynamics (QCD). 



QCD describes how quarks and gluons, the fundamental building blocks of protons and neutrons, interact.



Immediately following the Big Bang, physicists estimate that the universe was an immensely hot plasma of quarks and gluons that quickly cooled and combined to produce protons and neutrons. 



The researchers found that within the first quintillionth of a second, the universe would still have been a soup of free <a href="https://www.earth.com/news/gluons-quarks-and-mystery-what-makes-proton-spin/" target="_blank" rel="noreferrer noopener">quarks and gluons</a> that had yet to combine. 



Any black holes forming during this time would have swallowed up these untethered particles, along with an exotic property known as "color charge" - a state of charge that only uncombined quarks and gluons carry.



"Once we figured out that these black holes form in a quark-gluon plasma, the most important thing we had to figure out was, how much color charge is contained in the blob of matter that will end up in a primordial black hole?" explains Alonso-Monsalve.



<h2 class="wp-block-heading" id="h-exotic-color-charge-properties">Exotic color charge properties</h2>



Using QCD theory, Kaiser and Alonso-Monsalve worked out the distribution of color charge that should have existed throughout the hot, early plasma. 



They then compared that to the size of a region that would collapse to form a black hole in the first quintillionth of a second.



Interestingly, they found that most typical black holes at the time wouldn't have contained much color charge, as they would have formed by absorbing a huge number of regions with a mix of charges, ultimately adding up to a "neutral" charge.



However, the smallest black holes would have been packed with color charge. In fact, they would have contained the maximum amount of any type of charge allowed for a black hole, according to the fundamental laws of physics. 



These <a href="https://www.earth.com/news/black-holes-shaped-the-universe-before-galaxies-existed/" target="_blank" rel="noreferrer noopener">"extremal" black holes</a>, although hypothesized for decades, had never been linked to a realistic formation process in our universe until now.



<h2 class="wp-block-heading" id="h-searching-for-signs-in-the-form-of-imprints">Searching for signs in the form of imprints</h2>



The super-charged black holes would have quickly evaporated, but possibly only after the time when the first atomic nuclei began to form, around one second after the Big Bang. 



This would have given the extremal black holes ample time to disrupt the equilibrium conditions that would have prevailed when the first nuclei <a href="https://www.earth.com/news/early-black-holes-were-too-scarce-to-explain-the-unseen-universe/" target="_blank" rel="noreferrer noopener">began to form</a>.



"These objects might have left some exciting observational imprints," muses Alonso-Monsalve. "They could have changed the balance of this versus that, and that's the kind of thing that one can begin to wonder about."



Such disturbances could potentially affect how those earliest nuclei formed, in ways that might someday be observed by astronomers with future measurements. 



If such observations are made, they would point convincingly to primordial black holes as the root of all dark matter in the universe today.



<h2 class="wp-block-heading" id="h-dark-matter-the-universe-and-the-fabric-of-reality">Dark matter, the universe, and the fabric of reality</h2>



In summary, this important study by Kaiser and Alonso-Monsalve opens up a new frontier in our understanding of the early universe and the nature of dark matter. 



By exploring the formation and composition of primordial black holes, the researchers highlight a fascinating possibility that could revolutionize our understanding of the cosmos.



As we continue to unravel the mysteries of the universe, studies like this remind us of the incredible complexity and beauty that lies hidden in the fabric of reality. 



The quest to understand dark matter and the origins of the universe is an ongoing journey, and with each new discovery, we inch closer to unlocking the secrets of the cosmos.



The full study was published in the journal <a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.132.231402" target="_blank" rel="noreferrer noopener">Physical Review Letters</a>.



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Microscopic black holes may explain all dark matter in the universe

In the vast expanse of the cosmos, there is much...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Nushagak Bay, a large estuary in southwest Alaska. Nushagak runs mainly north to south and exits in Bristol Bay, a large body of water in the Bering Sea.



"The bay is primarily fed by the Nushagak River, which begins in the Alaska Range and flows southwest approximately 450 km. The bay is also fed by several additional rivers including the Wood, Igushik, Snake and Weary rivers," says ESA.



"The dark colors of the Nushagak River are most likely due to tannins or lignins (chemical substances found in plants). Tannins and lignins from roots, leaves, seeds, bark and soil can leach into the water and give it a brown or even black colour. The sediments then flow southwards where it is mixed with the bluer waters of the bay."



Video/ Image Credit: ESA



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nushagak Bay in southwest Alaska

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> (ACS) reveals that proteins on flu viruses are actually flexible, tilting and waving in a “breath-like” motion. According to the experts, these proteins could be used to better defend against the flu.



"The main antigenic targets of influenza virus are two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Whereas the structural and dynamical properties of both glycoproteins have been studied previously, the understanding of their plasticity in the whole-virion context is fragmented," wrote the researchers.



To investigate, the team conducted detailed simulations of the influenza A H1N1 virion, or the swine flu. The experts concluded that the visualizations show many new vulnerable states of flu viruses, which could improve future vaccines and antiviral drugs.



Video/ Image Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Flu viruses are more flexible than expected

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Lake Trasimeno, which is located west of Perugia in central Italy. It is the fourth largest lake in the country. While Trasimeno’s water level varies, it has a maximum depth of approximately six meters.&nbsp;



"In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark colored waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae," says ESA.



"Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno."



"Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022."



Video/Image Credit: ESA&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lake Trasimeno in Central Italy

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> describes a new self-powered nanosensor that can instantly detect mercury contamination with the tap of a finger.&nbsp;



The oxidized form of mercury can be harmful when it is ingested through contaminated water or food. This makes it necessary for experts to develop sensors that can quickly and accurately detect the presence of mercury.&nbsp;



Zong-Hong Lin and colleagues have now created a triboelectric nanosensor (TENS) that can detect mercury by simply by touching a sample. According to the researchers, their TENS could serve as the basis for similar devices to safely and remotely monitor other pollutants.



Video Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Detecting mercury contamination with the tap of a finger

[sendtonews key="LvS8v8bp9z-2564889-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> explores the ability of salt to transform the way that foods and beverages taste. Salt is known to cover up undesirable flavors, such as bitterness in coffee or beer, but how exactly does sodium chloride change the taste of other compounds?



One previous study showed that, not only does salt suppress bitterness, but also enhances sweetness and sourness. Another study revealed that bitterness reduction by salt seems to be happening at the tongue receptor level as well as in the brain.&nbsp;



While it is known that salt taste is mediated by the presence of sodium channels in the form of taste buds, experts believe that there is also an unknown receptor responsible for how we taste salt that has not yet been identified.&nbsp;



Video Credit: ACS Reactions



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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How does salt makes things taste better?

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Santiago, the capital city of Chile. The city is located in the center of the Santiago Metropolitan Region, which has a population of about eight million people.&nbsp;



'The weather of Santiago resembles the Mediterranean climate with dry and warm summers with temperatures reaching up to 35°C (from October to March) and cool and humid winters that can drop to 0°C (from April to September)."



"The city lies in the centre of the country’s central valley around 80 km from the Pacific Ocean to the west and borders Argentina to the east. A tiny part of Argentina is visible in the top-right corner of the image where the mountain crest of the Andes Mountains acts as a divider between the two countries," says ESA.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Santiago, Chile in South America

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Spiral,Galaxy,,Illustration,Of,Milky,Way

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Astronomers at <a href="https://www.jhu.edu/">Johns Hopkins University</a> have created an interactive map of the universe, including the actual position and real colors of 200,000 galaxies. The map allows the public to access data that was previously only available to scientists.



The map was developed using data collected by the Sloan Digital Sky Survey. For over two decades, a telescope in New Mexico was aimed at slightly different locations to capture the night sky.&nbsp;



"Growing up I was very inspired by astronomy pictures, stars, nebulae and galaxies, and now it's our time to create a new type of picture to inspire people," said map creator Brice Ménard, a professor at Johns Hopkins. "Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate, and accessible to people who are not scientists. Our goal here is to show everybody what the universe really looks like."



"In this map, we are just a speck at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way which has billions of stars and planets. We are used to seeing astronomical pictures showing one galaxy here, one galaxy there or perhaps a group of galaxies. But what this map shows is a very, very different scale."



"From this speck at the bottom, we are able to map out galaxies across the entire universe, and that says something about the power of science."



The <a href="https://mapoftheuniverse.net/">interactive map</a> is available online, where it can be downloaded for free.



Video Credit: Johns Hopkins&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Interactive map of the universe includes 200,000 galaxies

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Lesotho: Africa's "Kingdom in the Sky" Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features northwest Lesotho in South Africa.



According to ESA, Lesotho is the only nation in the world that lies completely above 1,000 m in elevation. The country is famous for its tall mountains and narrow valleys, and is known as Africa's "Kingdom in the Sky."



Out of a population of around two million people, about 80 percent live in rural areas. More than 75 percent of these people are engaged in <a href="https://www.earth.com/news/climate-change-will-have-a-global-impact-on-agriculture/">agriculture</a>, including rainfed cereal production and animal grazing.&nbsp;



ESA reports that the country’s agricultural system faces a growing number of issues, with climate-related vulnerabilities such as drought, floods and extreme temperatures occurring more frequently. 



Diamonds are amongst the minerals found in the mountains. Indeed, Lesotho can truly be called the Kingdom in the Sky. Beautiful, culturally rich, safe, affordable, and easily accessible from Durban and Johannesburg, mountainous Lesotho is a vastly underrated travel destination. the Kingdom of Lesotho (Sotho: 'Muso oa Lesotho) is an enclaved country in southern Africa. It is just over 30,000 km2 (11,583 sq mi) in size and has a population of around 2 million.



Video Credit: ESA&nbsp;&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer 



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Lesotho: Africa's "Kingdom in the Sky"

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Dublin, the capital and largest city of Ireland. Beyond its pub culture, Dublin is known as a modern culinary destination and a UNESCO City of Literature.



"Dublin is located near the midpoint of Ireland’s east coast in the province of Leinster. The city, which covers an area of around 115 square kilometers, is bordered by the Dublin Mountains, a low mountain range to the south, and is surrounded by flat farmland to the north and west," says ESA.



"The city straddles the River Liffey, which rises in the Wicklow Mountains and flows around 80 kilometers eastwards through the city of Dublin, in which it is canalised and bordered with quays. It then empties into Dublin Bay, an arm of the Irish Sea."



Dublin has an abundance of green spaces, including one of the largest enclosed public parks in any European capital city. Phoenix Park, which was originally formed as a royal hunting park in the 1660s, includes 707 hectares of green space.



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The city of Dublin on Ireland's east coast

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the province of Zaragoza in northeast Spain. The image was captured by the Copernicus Sentinel-2 mission.



"Together with the provinces of Huesca and Teruel, Zaragoza formed the old kingdom of Aragon. Its capital, also called Zaragoza (not visible in this image) is home to around half of Aragon’s population," says ESA.



"The Ebro River can be seen winding its way through the province from west to east in this image. Between its source in the Cantabrian Mountains in the northwest and its delta on the Mediterranean coast, the Ebro River is fed by more than 200 tributaries as it flows 910 km across much of northern Spain."



Since rainfall is very scarce in this region, irrigation in the Ebro basin is critically important. In the valleys surrounding the Ebro River, many fields are used for growing crops such as corn, wheat, and barley.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The province of Zaragoza in northeast Spain

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> reveals the evolution of the Columbia Glacier in southeastern Alaska. Columbia is among the fastest shrinking glaciers in the world, and the video documents its rapid retreat over the years.&nbsp;



Columbia Glacier is a large, multi-branched calving glacier that flows out of the Chugach Mountains to the Prince William Sound.&nbsp;



According to USGS, Columbia had a long history of stability prior to 1980, with a length 41 miles, and small, short-lived advances or retreats.



In the years since 1980, however, satellite images have captured Columbia’s alarming retreat. By using false-color images, scientists can distinguish between snow and ice, open water, vegetation, and rocky debris on the glacier’s surface.



The series of false-color images featured in today's video were acquired over the span of 35 years. You can see that by 2021, the glacier’s main branch had retreated about 15 miles from its initial position.



The Columbia Glacier has also lost more than 50 percent of its volume, mostly due to calving. <a href="https://www.earth.com/video/nasa-reveals-3d-visual-of-an-atmospheric-river/">NASA</a> reports that while climate change likely started the retreat, mechanical processes kept the disintegration going.



The NASA images are provided by Jesse Allen, Robert Simmon, Joshua Stevens, and Lauren Dauphin using data from Landsat satellites, from the U.S. Geological Survey, and data from MODIS on NASA’s Terra satellite. The structure of Columbia’s moraine played a large role in the stability of the glacier before 1980. 



Like other tidewater glaciers, the Columbia built up a moraine over time, and the mixture of ice and rock functioned like a dam keeping out the sea. It was supported on one end by the shoreline and by the underwater terminal moraine at the other.



Video Credit: NASA Earth Observatory/&nbsp; NASA’s Scientific Visualization Studio



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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The rapid retreat of the Columbia Glacier

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the Pyrenees Mountains, which form a natural boundary between France and Spain in southwest Europe.



The mountain range is 430 kilometers in length. It stretches from the Mediterranean Sea on the east to the Atlantic Ocean on the west.



At an elevation of 3404 meters, Pico de Aneto is the highest mountain peak in the Pyrenees, and the third-highest peak in Spain. Pico de Aneto is located in the Posets-Maladeta Natural Park, which spans more than 82,000 acres.&nbsp;



"Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras," reports ESA.



"The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water."



The western Pyrenees receive more precipitation due to moisture blowing in from the Atlantic Ocean. The mountain range contains many lakes, several small glaciers, and some of the highest waterfalls in Europe.



Video &amp; Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The Pyrenees Mountains in southwest Europe

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Earth,Like,Exoplanet,3d,Render

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are "water worlds."



The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.



"We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," explained study co-author Björn Benneke.&nbsp;



"However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time."



Video Credit: NASA Goddard



Image Credit: NASA, ESA, and Leah Hustak (STScI)



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Two distant planets may be "water worlds"

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Satellites reveal how Earth's systems are interconnected Today’s Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes Earth’s interconnected systems, and how this network is affected by rising temperatures.&nbsp;



During 2020, average global temperatures matched the hottest year on record. The hurricane season was also record-breaking, with many of the storms intensifying at extraordinary speeds. Hot water in the ocean is fuel for hurricanes. The satellite data shows that it's all one interconnected system showing how Satellites reveal how Earth's systems are interconnected.



According to NASA, dust swept up from Northern Africa plays a major role in the formation of hurricanes, and is also a key source of fertilization in the Amazon rainforest. As a result of<a href="https://www.earth.com/news/seagrass-wasting-disease-is-fueled-by-climate-change/"> climate</a> change, dust plumes are expected to decline, which will have an effect on vegetation far away.&nbsp;



Images from Earth-observing satellites show how the world’s plant life is affected by natural disasters, fires, and deforestation. Satellites also reveal how widespread changes in vegetation impact waterways,&nbsp; the climate, air quality. Satellites communicate by using radio waves to send signals to the antennas on the Earth. "Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. 



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites reveal how Earth's systems are interconnected

[sendtonews key="JbW4VsY53O-1632195-12187" type="single"] Satellites reveal how Earth's systems are interconnected...

Today’s Video of the Day from the <a href="https://welcome.miami.edu/">University of Miami</a> Rosenstiel School of Marine and Atmospheric Science explores how changes in water temperatures have affected tiger shark habitats and movements in the North Atlantic Ocean. The study reveals that rising temperatures have caused the sharks to shift toward the poles over the past 40 years.



“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” explained study lead author Neil Hammerschlag. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”



The researchers analyzed nine years of tracking data from satellite-tagged tiger sharks, combined with four decades of conventional tag and recapture data provided by National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program.



The experts found that during the last decade of record heat, for every one-degree Celsius increase in water temperatures, tiger sharks migrated further poleward by over 400 kilometers. They also migrated two weeks earlier than usual to waters off the northeastern coast of the United States.



“Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” concluded Professor Hammerschlag.



Video Credit: University of Miami Rosenstiel School of Marine and Atmospheric Science



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Tiger sharks are shifting poleward as temperatures rise

Today’s Video of the Day from the University of Miami...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> is focused on the melt ponds that emerge during the spring and summer on the Greenland Ice Sheet, which is the largest ice mass in the northern hemisphere.



"Melt ponds are vast pools of open water that form on both sea ice and ice sheets and are visible as turquoise-blue pools of water in this Copernicus Sentinel-2 image," says ESA.



"When snow and ice melts atop glaciers, water flows in channels and streams and collects in depressions on the surface. These melt ponds can speed up the melting of the surrounding ice since they greatly reduce the ice’s ability to reflect sunlight."



"This can create a positive feedback where an increasing number of melt ponds absorb more heat which causes ice cover to melt even faster."



According to ESA, Greenland has been hit with a late-season heatwave that began in early September. This caused the type of melt event that usually occurs in the middle of summer.



"In a recent paper published in Nature Climate Change, scientists found that major sea-level rise from the melting of the Greenland ice cap is now ‘inevitable’ even if the burning of fossil fuels were to halt overnight," says ESA. "Using satellite observations of Greenland ice loss and ice cap from 2000 to 2019, the team found the losses will lead to a minimum rise of 27 cm regardless of climate change."



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Melt ponds on the Greenland Ice Sheet

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes a new map of Mars that is providing insight into the planet’s watery past. The map also reveals where future missions could safely land on Mars.&nbsp;



The map has been created over the last decade using observations of water-rich rocks and mineral deposits. The images were captured by ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter.



"A big surprise is the prevalence of these minerals, with the map revealing hundreds of thousands of water-affected locations in the oldest parts of the planet," says ESA. "The new data will help answer exciting questions about Mars’ climate history, whether water was globally persistent or confined to short, intense episodes, and whether the conditions were ever suitable for life."



"Specifically, the map shows the locations and abundances of aqueous minerals. These are from rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts."



According to John Carter of the Institut d’Astrophysique Spatiale (IAS), our collective understanding of Mars has been oversimplified. He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period, then as the water gradually dried up, salts were produced across the planet.



The new map shows that the composition of Mars is much more complicated than what we thought. For example, while many salts formed after Martian clays, there are some salts that are presumed to be older than some of the clays.&nbsp;



“The evolution from lots of water to no water is not as clear cut as we thought, the water didn’t just stop overnight. We see a huge diversity of geological contexts, so that no one process or simple timeline can explain the evolution of the mineralogy of Mars. That’s the first result of our study. The second is that if you exclude life processes on Earth, Mars exhibits a diversity of mineralogy in geological settings just as Earth does,” said Carter.



Video Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The history of Mars is much more complex than we thought

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Today's Video of the Day from the <a href="https://www.stowers.org/">Stowers Institute for Medical Research</a> describes how cavefish adapted to a sedentary lifestyle over tens of thousands of years. 



The experts found that the muscle metabolism of cavefish has been genetically reprogrammed over time. As a result, the animals have experienced major changes in their morphology and behavior. Despite these changes, however, the cavefish remain healthy and fit.



The research may provide new clues about the evolutionary consequences of prolonged physical inactivity in humans.&nbsp;



“It’s no surprise that people are moving less and less as technology has advanced,” said Rohner. “With cavefish, we have a unique system where we can study what might happen if people remained couch potatoes over very, very long periods of time.”



Video Credit: Stowers Institute for Medical Research



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Cavefish are healthy despite their sedentary lifestyle

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> some of the most incredible waves in the world, as seen by Landsat satellites.



"With more than 370,000 miles of coastline on Earth, there are plenty of places where epic waves build up, curl over, and hurtle toward the shore.- much to the thrill of surfers," says NASA. "There are some places where these waves are so magnificent that they can be seen from space."



"With the broad perspective of satellites, we can see how these iconic waves develop into the world’s tallest, longest, fastest, and heaviest."



Video Credit: NASA Earth Observatory&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites capture the world's biggest and fastest waves

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes why satellite images and measurements of our planet have become "essential to our survival, offering a new outlook of our world."&nbsp;



Rising sea levels pose one of the biggest societal threats associated with climate change. According to ESA, satellite altimeter missions such as Copernicus Sentinel-6 are essential in monitoring global and regional changes in sea level.



"Unbeknown to many, the island of Crete, Greece, plays an important role in the Copernicus satellite altimetry constellation and on an international stage," reports ESA.



"Satellite altimetry data have to be continuously monitored at the ESA’s Permanent Facility for Altimetry Calibration where different techniques have pioneered the use of transponders to provide the best measurements to validate satellite altimeters in space soon after launch."



Dr. Craig Donlon explains that, by understanding planet Earth through satellite measurements, we are able to find evidence of change.&nbsp;



Video Credit: European Space Agency&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Satellites have become essential to our survival

[sendtonews key="761m2QQvR1-2035772-12187" type="single"] Today’s Video of the Day from the...