Today's Image of the Day from the European Space Agency features a pair of interacting spiral galaxies known as the Antennae Galaxies. They are located approximately 45 million light-years away in the constellation Corvus.&nbsp;



<h2 class="wp-block-heading" id="h-antennae-galaxies-in-a-deadly-embrace">Antennae Galaxies in a deadly embrace </h2>



“The NASA/ESA Hubble Space Telescope has snapped the best ever image of the Antennae Galaxies. Hubble has released images of these stunning galaxies twice before, once using observations from its Wide Field and Planetary Camera 2 (WFPC2) in 1997, and again in 2006 from the Advanced Camera for Surveys (ACS),” noted <a href="https://esahubble.org/images/potw1345a/" target="_blank" rel="noreferrer noopener">ESA</a>.



“The galaxies - also known as NGC 4038 and NGC 4039 - are locked in a deadly embrace. Once normal, sedate spiral galaxies like the Milky Way, the pair have spent the past few hundred million years sparring with one another.”



According to ESA, the clash of the Antennae Galaxies is so violent that stars have been ripped from their host <a href="https://www.earth.com/news/galaxy-collision-2-million-mph-stephans-quintet-captured-unprecedented-detail/" target="_blank" rel="noreferrer noopener">galaxies</a> to form a streaming arc between the two.&nbsp;



The name "Antennae" comes from this long stream of stars and gas, which resembles insect antennae.



<h2 class="wp-block-heading" id="h-intense-bursts-of-star-formation-nbsp">Intense bursts of star formation&nbsp;</h2>



The collision has triggered intense bursts of star formation, making the Antennae Galaxies one of the nearest and most dramatic examples of a starburst galaxy.&nbsp;



Many of the newly formed stars are concentrated in massive star clusters, some of which are expected to evolve into globular clusters over millions of years.



“This new image of the Antennae Galaxies shows obvious signs of chaos. Clouds of gas are seen in bright pink and red, surrounding the bright flashes of blue star-forming regions - some of which are partially obscured by dark patches of dust,” explained ESA.



“The rate of star formation is so high that the Antennae Galaxies are said to be in a state of starburst, a period in which all of the gas within the galaxies is being used to form stars.”&nbsp;



“This cannot last forever and neither can the separate galaxies; eventually the nuclei will coalesce, and the galaxies will begin their retirement together as one large elliptical galaxy.”



<h2 class="wp-block-heading" id="h-significance-of-the-antennae-galaxies">Significance of the Antennae Galaxies</h2>



The Antennae Galaxies are one of the most well-studied examples of galaxy collisions, offering insight into the processes that shape galaxies over time.



Astronomers study the Antennae Galaxies using a range of telescopes across different wavelengths, including visible light, infrared, and X-rays.&nbsp;



Observations in X-rays have revealed evidence of supernovae and <a href="https://www.earth.com/news/black-holes-may-talk-to-galaxies-through-energetic-winds/" target="_blank" rel="noreferrer noopener">black holes</a>, while infrared studies highlight regions of dust and star formation.&nbsp;



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



The Antennae Galaxies provide a glimpse into the future of our <a href="https://www.earth.com/news/uma3-u1-faintest-star-system-found-orbiting-milky-way-galaxy/" target="_blank" rel="noreferrer noopener">Milky Way</a>, which is expected to eventually merge with the Andromeda Galaxy - our closest spiral galaxy neighbor.



The cosmic collision course of the Milky Way and Andromeda will reshape both galaxies over billions of years.&nbsp;



This event is expected to occur in about 4.5 billion years. Both galaxies are part of the Local Group, a cluster of galaxies bound together by gravity. Their mutual gravitational pull is drawing them closer at a speed of approximately 110 kilometers per second.



<h2 class="wp-block-heading" id="h-the-birth-of-an-elliptical-galaxy-nbsp">The birth of an elliptical galaxy&nbsp;</h2>



When the two galaxies collide, their individual stars will largely avoid direct collisions due to the vast distances between them. However, the gravitational forces involved will create dramatic effects.&nbsp;



These forces will distort the galaxies' <a href="https://www.earth.com/news/shapes-of-one-million-galaxies-hint-at-the-universes-origins/" target="_blank" rel="noreferrer noopener">shapes</a>, triggering intense bursts of star formation as gas clouds collide and compress. Over time, the galaxies will settle into a new, larger elliptical galaxy often referred to as "Milkomeda" or "Milkdromeda" by astronomers.



<h2 class="wp-block-heading" id="h-galaxy-merger-and-the-solar-system">Galaxy merger and the solar system</h2>



Despite the seemingly destructive nature of the collision, the solar system is unlikely to face direct harm. Our Sun may find itself flung into a new orbit within the merged galaxy or even cast into intergalactic space.&nbsp;



The merger will also significantly alter the night sky, with the Andromeda Galaxy becoming increasingly prominent before blending into the unified structure.



This event is part of the natural <a href="https://www.earth.com/news/galaxies-are-much-bigger-than-we-originally-believed-gas-clouds/" target="_blank" rel="noreferrer noopener">evolution of galaxies</a> and serves as a fascinating reminder of the dynamic and ever-changing nature of the universe. 



While the collision is still billions of years away, studying it helps astronomers understand galactic interactions and the long-term future of our cosmic neighborhood.



Image Credit: ESA/Hubble &amp; NASA



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The violent clash of the Antennae Galaxies  

Today's Image of the Day from the European Space Agency...

Today's Image of the Day from the European Space Agency features a compilation of European cities that resemble stars. 



“Star-shaped cities are scattered across Europe, their geometric designs most appreciated when viewed from above,” noted <a href="https://www.esa.int/ESA_Multimedia/Images/2024/12/Earth_from_Space_Star_cities" target="_blank" rel="noreferrer noopener">ESA</a>. 



<h2 class="wp-block-heading" id="h-development-of-star-shaped-cities">Development of star-shaped cities</h2>



The development of star-shaped fortresses, also known as bastion forts, emerged during the Renaissance in Italy as a response to the rapidly evolving art of <a href="https://www.earth.com/news/migrating-eagles-have-been-rerouted-by-the-war-in-ukraine/" target="_blank" rel="noreferrer noopener">warfare</a>.&nbsp;



Traditional medieval fortifications, characterized by high, straight walls and square towers, became vulnerable with the advent of gunpowder weaponry. Cannons could easily reduce these structures to rubble, rendering them obsolete.



The star-shaped design addressed these vulnerabilities by incorporating wide moats and projecting bastions - angled structures that jutted outward from the main walls.&nbsp;



These bastions provided overlapping fields of fire, allowing defenders to cover blind spots and effectively repel attackers attempting to approach or scale the walls.&nbsp;



Additionally, the sloped walls of these fortresses, known as glacis, were designed to deflect cannonballs rather than absorb their impact, further enhancing their resilience.



This innovative design not only improved defensive capabilities but also transformed the battlefield, forcing attackers to develop new siege techniques. It marked a pivotal moment in military engineering, influencing fortress construction across Europe and beyond for centuries.



<h2 class="wp-block-heading" id="h-examples-of-star-shaped-cities">Examples of star-shaped cities</h2>



“Four examples of such cities can be seen here, arranged clockwise from the top left: Bourtange in the Netherlands, Palmanova in Italy, Almeida in Portugal, and Neuf-Brisach in France,” said ESA.



“The green and red hues evoke a Christmas vibe, achieved through different band combinations during image processing to generate true-color (green) and false-color (red) visuals.”



<h3 class="wp-block-heading" id="h-bourtange-netherlands">Bourtange, Netherlands </h3>



Fort Bourtange, nestled in the picturesque countryside of northeast Netherlands near the German border, is a remarkable example of Renaissance military architecture and urban planning.&nbsp;



Constructed in 1593 during the Eighty Years' War, it was strategically positioned to control the only road linking Germany to the Dutch city of Groningen - a vital route for military and trade purposes.&nbsp;



Its unique pentagonal, star-shaped design featured angled bastions, wide moats, and interconnected defensive structures, making it nearly impenetrable to enemy forces equipped with the era's artillery.



In 1851, after centuries of military service, Fort Bourtange was decommissioned and transformed into a peaceful village.&nbsp;



Despite the change in purpose, its original geometric layout, defined by precise angles and symmetrical patterns, remained intact. The pentagonal walls, surrounding waterways, and radial street design continue to showcase the ingenuity of its designers.



<h3 class="wp-block-heading" id="h-palmanova-italy">Palmanova, Italy </h3>



Palmanova, located in the Friuli-Venezia Giulia region of northeast Italy, is a masterpiece of Renaissance urban and military planning.&nbsp;



Designated as a UNESCO World Heritage site, it exemplifies the idealized city envisioned during the late Renaissance, combining beauty, functionality, and <a href="https://www.earth.com/news/preparing-u-s-military-bases-for-sea-level-rise/" target="_blank" rel="noreferrer noopener">military</a> innovation.&nbsp;



Constructed in 1593 by the Republic of Venice, Palmanova was strategically designed to protect the Republic’s northeastern borders from external threats - particularly the Ottoman Empire.



The city’s layout embodies the principles of symmetry and order characteristic of the Renaissance. Its unique radial design spreads out from the central hexagonal square, known as Piazza Grande or Piazza del Duomo, which serves as the civic and social heart of the city.&nbsp;



From this central hub, six straight avenues fan outward, connecting the square to the surrounding neighborhoods and gates. This design was not only aesthetically pleasing but also practical, allowing for efficient movement and communication within the city.



Today, Palmanova is celebrated not only for its historical and architectural significance but also as a rare example of a perfectly preserved star fortress.&nbsp;



<h3 class="wp-block-heading" id="h-almeida-portugal-nbsp">Almeida, Portugal&nbsp;</h3>



Perched on a high plain in northeast Portugal near the Spanish border, the fortress of Almeida is a striking example of military engineering and a symbol of Portugal’s resilience.&nbsp;



Built to secure the nation’s eastern frontier, Almeida has played a significant role in Portuguese history, particularly during its early years of independence and throughout various military conflicts, including the Peninsular War.



The fortress's defining star-shaped ramparts consist of twelve points, each projecting outward to eliminate blind spots and provide overlapping fields of fire against advancing enemies.&nbsp;



The thick walls, surrounding moats, and angular bastions made Almeida a formidable stronghold capable of withstanding prolonged sieges.



<h3 class="wp-block-heading" id="h-neuf-brisach-france">Neuf-Brisach, France</h3>



Neuf-Brisach, located in the Alsace region of northeastern <a href="https://www.earth.com/news/470-million-year-old-animal-fossils-discovered-in-frances-cabrieres-biota/" target="_blank" rel="noreferrer noopener">France</a> near the German border, is another fascinating example of military and urban design.&nbsp;



The town was constructed in 1697 after the loss of Breisach, which stood on the opposite bank of the Rhine River in Germany.&nbsp;



The name "Neuf" (meaning "new" in French) reflects its creation as a strategic replacement and fortification to strengthen France's defense along its eastern border.



Designed by Sébastien Le Prestre de Vauban, the renowned military engineer under King Louis XIV, Neuf-Brisach is part of the extensive network of fortifications that Vauban designed to protect France from external threats.&nbsp;



Vauban's expertise in defensive architecture is evident in the town's star-shaped layout, which was intended to optimize defense while accommodating civilian life within the fortifications.&nbsp;



The fortifications were built to withstand sieges and were strategically positioned to control movement across the Rhine River and defend against potential invasions. The outer star-shaped ramparts extend in a way that creates a nearly impenetrable defensive perimeter.



Image Credit: European Space Agency&nbsp;



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Star-shaped cities scattered across Europe

Today's Image of the Day from the European Space Agency features a Copernicus Sentinel-2 photograph of Lake Maracaibo, located in the northwestern part of Venezuela. The lake is a significant geographical and ecological feature of South America. 



Lake Maracaibo is often considered more of a tidal bay due to its direct connection to the Caribbean Sea through the Tablazo Strait. It is one of the oldest lakes on Earth, formed approximately 36 million years ago.



"With an area of over 13,000 sq km, Lake Maracaibo is generally considered the largest lake in South America, although by some estimates it should be considered an inlet of the Caribbean Sea since much of its water is brought in by its direct connection to the ocean," explained <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>.



"As a result, the water in the northern part of the lake is rather brackish, while the southern waters are fresh, owing to the many rivers that flow into the lake. The biggest, the Catatumbo River, can be seen entering the lake from southwest, where a large amount of sediment carried by the river appears as a yellowish plume."



<h2 class="wp-block-heading" id="h-the-catatumbo-lightning">The Catatumbo lightning</h2>



The lake is renowned for a unique weather phenomenon - the Catatumbo lightning. This natural spectacle occurs primarily where the Catatumbo River meets the <a href="https://www.earth.com/news/wildfire-smoke-has-affected-almost-every-lake-in-north-america/" target="_blank" rel="noreferrer noopener">lake</a>.



Known as the most persistent lightning storm in the world, it produces frequent and dramatic flashes of lightning, illuminating the night sky for an average of 260 nights per year.



These storms generate thousands of lightning strikes in a single night, making the region one of the most electrified places on the planet. 



The phenomenon is so intense that it has been recognized by the Guinness World Records as the place with the highest <a href="https://www.earth.com/news/lightning-on-earth-can-influence-the-weather-in-space/" target="_blank" rel="noreferrer noopener">lightning</a> activity.



Scientists believe the lightning is influenced by the area's geography and climate, including the warm air rising from the lake and its surrounding mountains.



<h2 class="wp-block-heading" id="h-economical-significance-of-lake-maracaibo">Economical significance of Lake Maracaibo </h2>



Lake Maracaibo plays an important role in Venezuela’s economy, as it lies atop vast reserves of crude oil.



The discovery of petroleum in the early 20th century transformed the region into a major oil-producing area, leading to the establishment of numerous oil rigs and platforms. 



However, this economic activity has come at a cost. <a href="https://www.earth.com/news/half-of-the-worlds-largest-lakes-are-losing-their-resilience/" target="_blank" rel="noreferrer noopener">Pollution</a> from oil spills, industrial waste, and agricultural runoff has significantly degraded the lake's ecosystem.



The appearance of a green, slimy algae known as Lemna has further exacerbated environmental concerns, threatening marine life and the livelihoods of local communities.



<h2 class="wp-block-heading" id="h-cultural-ties-to-lake-maracaibo">Cultural ties to Lake Maracaibo </h2>



The cultural significance of Lake Maracaibo is deeply rooted in the traditions and lifestyle of the Indigenous Añu people, who have inhabited its shores for centuries. The Añu, also known as Paraujano, are known for their distinctive stilt houses, called palafitos.



These wooden structures are built directly over the water, connected by walkways or small boats, allowing the Añu to live harmoniously with their aquatic environment. The architectural style of these stilt houses inspired the early Spanish explorers to nickname the region "The Venice of the Americas."



The Añu's way of life is closely tied to the lake. They rely on <a href="https://www.earth.com/news/sustainable-fishing-must-be-redefined-to-halt-ocean-destruction/" target="_blank" rel="noreferrer noopener">fishing</a> as a primary source of food and income, using traditional methods passed down through generations.



For the Añu, the <a href="https://www.earth.com/news/wildfire-smoke-significantly-impacts-lake-ecosystems/" target="_blank" rel="noreferrer noopener">lake</a> is more than a resource; it is a spiritual and cultural cornerstone, shaping their identity and daily practices.



However, modernization and environmental challenges have disrupted their traditional lifestyle. The oil industry’s expansion around Lake Maracaibo has led to significant environmental degradation, which threaten the lake's biodiversity and the Añu’s primary sources of sustenance. 



<h2 class="wp-block-heading" id="h-lake-maracaibo-and-venezuelan-history">Lake Maracaibo and Venezuelan history</h2>



Lake Maracaibo also played a pivotal role in Venezuelan history, particularly during the Battle of Lake Maracaibo in 1823. 



This naval battle was a decisive conflict in Venezuela’s war for independence from Spain and marked one of the final military engagements of the South American liberation movements led by figures like Simón Bolívar.



Today, the lake represents a remarkable blend of natural beauty, industrial significance, and cultural heritage. 



<h2 class="wp-block-heading" id="h-ongoing-conservation-efforts">Ongoing conservation efforts </h2>



Ongoing efforts aim to harmonize ecological conservation with economic development, as both local and global stakeholders acknowledge the need to protect this extraordinary environment for generations to come.



Efforts to preserve the Añu culture and the lake's ecosystem have been initiated by local and international organizations. These initiatives focus on promoting sustainable development, preserving Indigenous languages and traditions, and mitigating the environmental damage caused by industrial activities. 



Despite these challenges, the Añu have shown remarkable resilience, maintaining their cultural identity and advocating for their rights and the health of their ancestral lands.



Image Credit: ESA



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Lake Maracaibo: One of the most electrified places on the planet

Today's Image of the Day from NASA Earth Observatory features a satellite view of retreating glaciers in Alaska, where meltwater is rapidly expanding glacial lakes. The image was captured on August 4, 2024 by the Landsat 8 satellite.



“In parts of Alaska, water is replacing ice. As glaciers thin and <a href="https://www.earth.com/news/satellite-images-reveal-hidden-retreat-of-arctic-glaciers/" target="_blank" rel="noreferrer noopener">retreat</a>, meltwater collects at their fronts, forming proglacial lakes. According to an analysis by Mauri Pelto, a glaciologist at Nichols College, three such lakes in the southeastern part of the state have grown rapidly in recent decades,” said <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA</a>.



<h2 class="wp-block-heading" id="h-retreating-glaciers-in-alaska">Retreating glaciers in Alaska</h2>



“A trio of glaciers - Yakutat, Alsek, and Grand Plateau - descend from inland mountains and flow onto the coastal plain southeast of Yakutat borough, ending at Harlequin Lake, Alsek Lake, and Grand Plateau Lake,” noted NASA.&nbsp;



The retreat of the glaciers, as well as the growth of the lakes, are visible in the image. When compared to an <a href="https://eoimages.gsfc.nasa.gov/images/imagerecords/153000/153638/fastestlake_tm5_19840705_lrg.jpg" target="_blank" rel="noreferrer noopener">image</a> captured by Landsat 5 in the summer of 1984, the changes are even more evident.



NASA elaborated on the extent of the glacier retreat from 1984 to 2024. “During this period, Yakutat Glacier’s main arm retreated 4.3 miles, while Alsek Glacier’s northern and southern arms retreated 3.3 miles and 3.4 miles, respectively. Grand Plateau Glacier’s northern arm lost the most, retreating 4.8 miles.”



<h2 class="wp-block-heading" id="h-glacial-lakes-doubled-in-size-nbsp">Glacial lakes doubled in size&nbsp;</h2>



“Collectively, the three lakes more than doubled in size over 40 years. In 1984, they covered about 50 square miles. By 2024, they spanned 90 square miles. That’s an area larger than Seneca Lake (67 square miles) - one of the Finger Lakes in New York, which also have a glacial origin,” said NASA.



Pelto noted that the lakes forming in this region are immense - starting at the mountains and spreading toward the coast - making this a new lake district that is unique in our nation.



“Millions of other lakes, named and unnamed, dot the state. But this system has grown fast, so much so that Pelto thinks it might represent the fastest lake growth in the United States this century,” said NASA.



<h2 class="wp-block-heading" id="h-understanding-glacier-retreat-nbsp">Understanding glacier retreat&nbsp;</h2>



Glacier retreat is a significant phenomenon driven primarily by global warming the results from rising greenhouse gas <a href="https://www.earth.com/news/global-carbon-dioxide-emissions-hit-a-record-high-in-2023/" target="_blank" rel="noreferrer noopener">emissions</a>.&nbsp;



As temperatures rise, glaciers lose more ice during the summer melt than they can regain in winter snowfall, causing them to shrink over time. This process has profound implications for ecosystems, water resources, and global sea levels.



<h3 class="wp-block-heading" id="h-glacial-lakes">Glacial lakes</h3>



When glaciers retreat, they often leave behind depressions in the landscape that can fill with meltwater, forming glacial lakes. These lakes are typically bounded by natural dams made of rock, ice, or moraine - accumulations of debris left behind by the glacier's movement.&nbsp;



Over the past century, the number and size of glacial lakes worldwide have increased significantly due to the accelerating pace of <a href="https://www.earth.com/news/tropical-glaciers-offer-a-glimpse-of-our-harsh-climate-reality/" target="_blank" rel="noreferrer noopener">glacier</a> retreat. This trend is especially evident in high-altitude regions like the Himalayas, the Andes, and the Alps, as well as in polar areas such as Alaska and Greenland.



<h3 class="wp-block-heading" id="h-positive-and-negative-impacts-nbsp">Positive and negative impacts&nbsp;</h3>



Glacial lakes can have both positive and negative impacts. They provide critical water sources for downstream communities, support biodiversity, and sometimes offer opportunities for hydropower development or tourism.&nbsp;



However, they also pose serious risks. The dams holding back these lakes can fail suddenly, causing glacial lake outburst floods (GLOFs). These catastrophic events can devastate downstream areas, destroying infrastructure, agricultural lands, and habitats while endangering human lives.



<h3 class="wp-block-heading" id="h-monitoring-changes">Monitoring changes</h3>



Understanding glacier retreat and glacial lake formation requires a multidisciplinary approach, combining climate science, hydrology, and geology.&nbsp;



Monitoring these changes is essential to mitigate associated risks and adapt to the evolving landscape shaped by a <a href="https://search.app?link=https%3A%2F%2Fwww.earth.com%2Fnews%2Fperu-has-lost-over-half-of-its-glaciers-in-six-decades%2F&amp;utm_campaign=aga&amp;utm_source=agsadl2%2Csh%2Fx%2Fgs%2Fm2%2F4" target="_blank" rel="noreferrer noopener">warming planet</a>.



<h2 class="wp-block-heading" id="h-glacier-retreat-worldwide">Glacier retreat worldwide</h2>



Studies and satellite observations show that most glaciers in almost all regions of the world are shrinking.&nbsp;



Melting glaciers contribute significantly to global <a href="https://www.earth.com/news/emergency-meeting-reveals-the-alarming-extent-of-antarcticas-ice-loss/" target="_blank" rel="noreferrer noopener">sea level rise</a>, which threatens coastal communities and ecosystems.



The retreat of glaciers is considered one of the clearest indicators of climate change.&nbsp;Some glaciers are retreating at unprecedented rates, indicating accelerating climate impacts.



Image Credit: NASA Earth Observatory



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Retreating glaciers and expanding meltwater lakes in Alaska

Today's Image of the Day from NASA Earth Observatory features...

Today's Image of the Day from NASA Earth Observatory features the Gobi Altai Mountains and neighboring plains covered in snow and illuminated by sunlight. 



The photograph was captured on January 25, 2024 as the International Space Station (ISS) passed over central Mongolia.



<h2 class="wp-block-heading" id="h-mountain-peaks-and-plains">Mountain peaks and plains</h2>



“Late-afternoon sunlight casts long shadows of mountain peaks onto the plains below. Numerous steep gullies cut into the massif, or mass of mountains, whose rugged appearance contrasts with the flat plains stretching along the top of the image,” said <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA</a>. “The plains are a semidesert grassland, or steppe, which provides pasture for livestock herders in the region.”



“The grassland surrounding the massif is classified by scientists as a cold semidesert. At an elevation of about 1,250 meters, annual temperatures are much lower there than in the mountains. The highest peak in the massif, Ikh Bogd (also known as Tergun Bogd), reaches nearly 4,000 meters.”&nbsp;



According to NASA, the climate on the peaks is classified as a polar tundra because the average annual temperature is below freezing. "Asia’s main tundra zone is located in Siberia, along the coast of the Arctic Ocean, 2,800 kilometers (1,750 miles) to the north.”



<h2 class="wp-block-heading" id="h-harsh-winters-and-livestock-in-mongolia">Harsh winters and livestock in Mongolia</h2>



Harsh <a href="https://www.earth.com/news/why-winters-are-getting-colder-while-world-is-getting-warmer/" target="_blank" rel="noreferrer noopener">winters</a> in Mongolia, locally known as "dzud," pose significant challenges for livestock and the herders who depend on them for their livelihood. These winters can be particularly severe, characterized by extreme cold, heavy snowfall, and ice, which can block access to grazing grounds, leaving animals without enough food.&nbsp;



The cold temperatures and nutritional shortages result in high mortality rates among livestock, which are crucial to the Mongolian economy and the nomadic lifestyle of many of its people.



The impact of these harsh winters extends beyond immediate animal welfare. As <a href="https://www.earth.com/news/bacteria-in-livestock-are-major-drivers-of-antibiotic-resistance/" target="_blank" rel="noreferrer noopener">livestock</a> numbers dwindle, herders face financial hardships, and the ripple effects can be felt throughout the entire community.&nbsp;



To combat these challenges, various strategies have been employed, including the development of better forecasting and early warning systems, the stockpiling of fodder, and improved veterinary care. These measures aim to strengthen the resilience of herding communities and ensure the survival of their livestock during Mongolia's most challenging seasons.



<h2 class="wp-block-heading" id="h-diverse-wildlife-of-mongolia">Diverse wildlife of Mongolia</h2>



Mongolia is renowned for its diverse wildlife, adapted to its unique landscapes ranging from vast steppes to rugged <a href="https://www.earth.com/news/mountains-both-carbon-sinks-and-carbon-sources/" target="_blank" rel="noreferrer noopener">mountains</a> and arid deserts. Among the most iconic species is the Bactrian camel, native to the region and crucial to nomadic herders.&nbsp;



The resilient Mongolian horse, integral to local culture, is celebrated for its endurance across the vast, open landscapes. Predators such as the snow leopard roam the high altitudes, playing a key role in the ecosystem, while the elusive Gobi bear survives in the sparse vegetation of the Gobi Desert.



The steppes are home to the fast-moving Mongolian gazelle and the critically endangered saiga antelope, known for its distinctive nose. The mountains support populations of argali sheep, the world's largest wild sheep, and the ibex, which has mastered the art of navigating rocky terrains. 



<h2 class="wp-block-heading" id="h-valley-of-lakes">Valley of Lakes</h2>



“Part of a small dry lake appears in the top left of the image. In wetter years, water from this lake feeds Orog Lake (also photographed by astronauts), out of frame to the upper right. This and other nearby lakes are part of the Valley of Lakes waterfowl conservation habitat, protected as a Ramsar site,” noted NASA.



The Valley of Lakes is known for its expansive <a href="https://www.earth.com/news/the-potential-of-tidal-wetlands-as-blue-carbon-ecosystems/" target="_blank" rel="noreferrer noopener">wetlands</a> and diverse ecosystems that support a variety of bird species, especially migratory waterfowl. This area serves as a crucial stopover for birds during their migration periods, providing them with essential resources such as food and shelter.&nbsp;



The conservation efforts in the Valley of Lakes focus on maintaining and restoring these <a href="https://www.earth.com/news/coastal-wetlands-are-inching-closer-to-extinction-as-the-world-heats-up/" target="_blank" rel="noreferrer noopener">wetlands</a> to ensure they continue to offer a safe haven for waterfowl. These efforts include controlling invasive plant species that threaten the natural vegetation and managing water levels to create optimal conditions for bird populations.&nbsp;



Education and community involvement are also key components of the conservation strategy, aiming to raise awareness about the importance of these habitats and encourage sustainable practices that help protect the local wildlife.



Image Credit: NASA Earth Observatory&nbsp;



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Mountain peaks and plains of central Mongolia 

Today's Image of the Day from the European Space Agency features the barred spiral galaxy NGC 1559, located around 35 million light-years away in the southern constellation Reticulum. The image was captured by the James Webb Space Telescope. 



<h2 class="wp-block-heading" id="h-fuel-for-star-formation">Fuel for star formation </h2>



"The data featured in this portrait make use of two of Webb’s instruments: the Mid-InfraRed Instrument (MIRI) and Near-InfraRed Camera (NIRCam)," noted <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>.



"Here MIRI captures the glow of interstellar dust grains, which trace out the interstellar medium, the fuel for future star formation. NIRCam shows the light from stars, even young stars hidden behind prodigious amounts of dust. NIRCam also captures emission from ionised nebulae around young stars."



<h2 class="wp-block-heading" id="h-webb-reveals-galaxies-in-new-light">Webb reveals galaxies in new light</h2>



According to ESA, the data was collected by the <a href="https://sites.google.com/view/phangs/home">PHANGS team</a> as part of a program in which Webb will observe 55 <a href="https://www.earth.com/news/james-webb-captures-galaxies-that-are-too-old-to-exist/">galaxies</a> that have also been mapped by the Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope, the Hubble Space Telescope, and more.&nbsp;



"By combining Webb’s unprecedented view of the dust and stars with data from these other facilities, the team aims to obtain a new, highly detailed view of how stars are born, live, and die in galaxies across the Universe."



<h2 class="wp-block-heading" id="h-ngc-1559-a-loner-in-space">NGC 1559: A loner in space</h2>



Although NGC 1559 appears to sit close to one of our nearest neighbors in the sky - the Large Magellanic Cloud (LMC) - this is just a trick of perspective, noted ESA.



While it is part of the Reticulum constellation, NGC 1559 is not part of the Local Group of galaxies but instead resides in a more distant region of space.



"In reality, NGC 1559 is physically nowhere near the LMC in space; in fact it truly is a loner, lacking the company of any nearby galaxies or membership of any galaxy cluster."



<h2 class="wp-block-heading" id="h-star-formation-in-ngc-1559">Star formation in NGC 1559</h2>



NGC 1559 is notable for its active star formation and strong magnetic fields. It has also been the site of several <a href="https://www.earth.com/news/supernova-explosions-could-damage-distant-planets/" target="_blank" rel="noreferrer noopener">supernovae</a>, making it of particular interest to astronomers studying stellar evolution and the lifecycle of stars.



The structure of NGC 1559 includes well-defined spiral arms that are rich in young, hot stars and regions of ionized gas, indicative of ongoing <a href="https://www.earth.com/news/black-hole-is-starving-its-host-galaxy-of-star-forming-fuel/" target="_blank" rel="noreferrer noopener">star formation</a>.



The galaxy’s central bar is believed to play a role in driving gas towards the core, fueling both the star formation and the activity around its nucleus.



<h2 class="wp-block-heading" id="h-an-extragalactic-wonder">An extragalactic wonder</h2>



Despite being relatively small compared to larger galaxies like the Milky Way, NGC 1559 is an important object for understanding how barred spiral galaxies evolve and the processes that trigger supernovae.



The galaxy’s remote location and active nature make it a fascinating subject of study in the field of extragalactic astronomy. The isolation of NGC 1559 allows for a clearer view of its structure without much interference from neighboring galaxies.



<h2 class="wp-block-heading" id="h-barred-spiral-galaxies">Barred spiral galaxies</h2>



Barred spiral galaxies are a type of spiral galaxy characterized by a central bar-shaped structure composed of stars. This bar extends out from the core and connects to the galaxy's spiral arms, which swirl outward in a graceful pattern.



Scientists believe that the bar plays a crucial role in the evolution of the galaxy, funneling gas towards the core and potentially triggering star formation or feeding a central black hole. 



The <a href="https://www.earth.com/news/newly-discovered-stars-milky-way-are-old-as-universe/" target="_blank" rel="noreferrer noopener">Milky Way</a>, our own galaxy, is an example of a barred spiral. These galaxies are quite common in the universe, making up about two-thirds of all observed spiral galaxies.



The bar itself is thought to be a temporary feature, developing as the galaxy matures and possibly disappearing over time as the dynamics of the stars change. 



<h2 class="wp-block-heading" id="h-the-reticulum-constellation">The Reticulum constellation</h2>



The Reticulum constellation is a small, faint constellation in the southern sky. Its name means "the reticle" in Latin, which refers to the crosshairs in an eyepiece of a telescope. 



The constellation was named in the 18th century by the French astronomer Nicolas Louis de Lacaille to honor the reticle he used in his scientific instruments. It is one of the 88 modern constellations recognized by the International Astronomical Union.



Image Credit: ESA/Webb, NASA &amp; CSA, A. Leroy, J. Lee and the PHANGS Team



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Spiral galaxy NGC 1559 is a loner in outer space

In yet another Edward S. Curtis photo, distinguished Native American chiefs gather in around 1900. Starting from the left, we have Little Plume of the Piegan, Buckskin Charley from the Ute, the great Chiricahua Apache leader Geronimo, Comanche chief Quanah Parker, Hollow Horn Bear of the Brulé Sioux, and the Oglala Sioux American Horse. And even though this photograph is obviously posed, it’s still truly splendid. Photo Credit: Edward S. Curtis

Chiefs

The world’s largest iceberg has astonished scientists by shaking free from a spinning ocean trap and continuing its trek across remote southern waters.



Its journey, marked by twists and turns since it separated from Antarctica, has become a focus for research on the changing ocean and the ice’s influence on life beneath the surface.



<h2 class="wp-block-heading" id="h-a23a-iceberg-breaks-free">A23a iceberg breaks free</h2>



The icy slab covers about 1,418 square miles, which makes it bigger than Rhode Island. 



It originally broke away from <a href="https://eros.usgs.gov/earthshots/filchner-ice-shelf-antarctica" target="_blank" rel="noreferrer noopener">Antarctica’s Filchner-Ronne Ice Shelf</a> in 1986 and remained stuck close to the continent for decades. 



Ocean currents and seafloor topography restricted its path. After finally regaining momentum last year, the towering block ran into a swirling formation of water near the <a href="https://www.ndsu.edu/subantarctic/southorkney.htm">South Orkney Islands</a>, where it ended up spinning in place for months.



<h2 class="wp-block-heading" id="h-tracking-iceberg-movements">Tracking iceberg movements</h2>



“It’s exciting to see A23a on the move again after periods of being stuck,” said <a href="https://www.bas.ac.uk/media-post/worlds-largest-iceberg-a23a-breaks-free/">Dr Andrew Meijers</a>, an oceanographer at the <a href="https://www.bas.ac.uk/" target="_blank" rel="noreferrer noopener">British Antarctic Survey</a>.



Ocean experts have been monitoring this <a href="https://www.earth.com/news/worlds-largest-iceberg-a23a-undergoing-major-erosion/" target="_blank" rel="noreferrer noopener">iceberg’s</a> every move to understand how such massive blocks can influence sea circulation, temperature balance, and the distribution of nutrients.



<h2 class="wp-block-heading" id="h-new-chapter-for-the-a23a-iceberg">New chapter for the A23a iceberg</h2>



The <a href="https://www.earth.com/news/birth-of-an-iceberg-a-83-breaks-free-from-antarctica/" target="_blank" rel="noreferrer noopener">iceberg’s</a> latest departure from its watery prison has stirred up fresh discussions about its fate. 



As it progresses northward, warmer seas may take a toll on its bulk. Many large ice masses follow a similar route before gradually disintegrating. Scientists emphasize that ice already afloat in the water does not raise sea levels when it melts. That does not mean these events should be dismissed, though, since Antarctica’s overall health is a concern in a warming world.



<h2 class="wp-block-heading" id="h-a23a-iceberg-and-its-ocean-impacts-nbsp">A23a iceberg and its ocean impacts&nbsp;</h2>



Researchers have pointed out that although this particular <a href="https://www.earth.com/news/iceberg-that-weighs-more-than-the-eiffel-tower-is-floating-freely/" target="_blank" rel="noreferrer noopener">iceberg</a> calved naturally, Antarctic ice shelves are showing other, more concerning changes.



Experts worry that accelerated ice loss in certain areas could have far-reaching effects. Even small changes along coastal regions of the continent can result in shifts in glacial flow, which might eventually lead to an uptick in sea-level rise. 



Data gathered from icebergs like A23a helps build a clearer picture of these wider trends.



<h2 class="wp-block-heading" id="h-importance-of-antarctic-ice-shelves">Importance of Antarctic ice shelves</h2>



These massive floating ice platforms act as natural barriers, holding back glaciers from flowing too quickly into the ocean, while playing a crucial role in our planet's climate system.



By doing this, they help regulate sea levels and prevent dramatic rises that could flood coastal communities around the world. 



Additionally, ice shelves influence <a href="https://www.earth.com/news/antarctica-ice-shelves-melting-faster-due-to-ocean-currents/" target="_blank" rel="noreferrer noopener">ocean currents</a> and the global climate by interacting with surrounding water and air, helping to maintain temperature and weather patterns. 



Without these ice shelves, we could see much faster ice loss from the Antarctic, leading to significant changes in our global climate.



Beyond their impact on climate, <a href="https://www.earth.com/news/antarctic-ice-shelves-are-fracturing-from-meltwater-weight/" target="_blank" rel="noreferrer noopener">Antarctic ice shelves</a> are vital indicators of environmental health. Scientists closely monitor these ice structures to understand the effects of global warming and to predict future changes in ice behavior. 



When ice shelves start to thin or collapse, it signals shifts in climate trends, providing valuable data for researchers working on climate models and sea-level rise projections.



Moreover, the areas beneath and around ice shelves host unique marine ecosystems that support a variety of wildlife, contributing to Earth’s biodiversity. 



<h2 class="wp-block-heading" id="h-ecosystems-under-the-ice">Ecosystems under the ice</h2>



Observations have shown that drifting ice blocks can stir the waters they pass through, sometimes generating short-lived plankton blooms. 



These blooms support fish, krill, and other marine life in areas that might otherwise lack resources. "These icebergs provide different sources of nutrients," explained Professor <a href="https://www.bas.ac.uk/profile/gant/" target="_blank" rel="noreferrer noopener">Geraint Tarling</a>, Biopole's principal investigator. By sampling the water where the giant iceberg has traveled, scientists hope to gauge whether this berg’s size and origin play a notable part in shaping ocean communities.



<h2 class="wp-block-heading" id="h-what-the-future-holds">What the future holds</h2>



Many anticipate that <a href="https://www.earth.com/news/a23a-worlds-largest-iceberg-is-moving-after-30-years/" target="_blank" rel="noreferrer noopener">A23a</a> will continue meandering through the Southern Ocean currents. As it ventures closer to milder latitudes, the ice is expected to weaken and break into smaller chunks. 



Some fragments may persist for a while, but the main body of the iceberg will likely diminish.



<h2 class="wp-block-heading" id="h-a23a-iceberg-research-enhances-ocean-circulation">A23a iceberg research enhances ocean circulation</h2>



Ongoing research on these gargantuan ice blocks helps experts refine climate models, track ocean circulation patterns, and pinpoint areas most vulnerable to environmental changes. 



Observations from ships, satellites, and on-site measurements all combine to offer a clearer view of what is happening far from major population centers. The hope is that findings from the watery trails left by A23a will guide future decisions on how we manage and protect polar waters and fragile marine habitats.



<h2 class="wp-block-heading" id="h-moving-lab-for-ocean-studies">Moving lab for ocean studies</h2>



A23a’s odyssey is important because it shows how an individual iceberg can become a moving lab for oceanographers and climate scientists. 



The iceberg's escape from a rotating water column this month hints at nature’s complexity, from shifting ocean currents to unseen underwater topography.



While it has been around for nearly four decades, its path in the coming months may reveal more about the chain reactions set in motion when a piece of Antarctica sets sail for open waters.



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World’s largest iceberg breaks free from ocean cyclone

The world’s largest iceberg has astonished scientists by shaking free...

Parker,Solar,Probe,Near,The,Sun.,Elements,Of,This,Image

NASA’s Parker Solar Probe touched the Sun's atmosphere, flying within 3.8 million miles (around 6.1 million kilometers) from the surface of the Sun on Tuesday, Dec. 24, at 6:53 a.m. EST. 



To approach the sun so closely, the Parker Solar Probe had to withstand extreme heat and intense radiation like no other spacecraft before it. 



"It is breaking all of these records and it's a, just a total 'Yay! We did it!' moment," <a href="https://science.nasa.gov/people/nicola-fox/" target="_blank" rel="noreferrer noopener">Nicola Fox</a>, the associate administrator for NASA Science Mission Directorate, said in a <a href="https://x.com/NASASun/status/1871524544306909200" target="_blank" rel="noreferrer noopener">video</a> on Dec. 24.



During its closest approach, also called perihelion, mission operations will be out of contact with the spacecraft. 



Scientists won’t know if Parker survived or what condition it’s in until Friday, when it's expected to send its first signal back to Earth since its close fly-by. Lots of fingers will remain crossed until then.



<h2 class="wp-block-heading" id="h-going-where-no-human-made-object-has-gone">Going where no human-made object has gone</h2>



This approach is unlike anything previously accomplished by a human-made spacecraft, marking a landmark in solar science that may rewrite much of what we know about our star.



Arik Posner, <a href="https://parkersolarprobe.jhuapl.edu/" target="_blank" rel="noreferrer noopener">Parker Solar Probe</a> program scientist at NASA Headquarters in Washington, sees this effort as a new window into solar research. “This is one example of NASA’s bold missions, doing something that no one else has ever done before to answer longstanding questions about our universe,” said <a href="https://science.nasa.gov/people/dr-arik-posner/" target="_blank" rel="noreferrer noopener">Arik</a>. The Johns Hopkins Applied Physics Laboratory (<a href="https://www.jhuapl.edu/" target="_blank" rel="noreferrer noopener">APL</a>) in Laurel, Maryland, manages mission operations and is keeping a watchful eye on every step as Parker speeds by.



<h2 class="wp-block-heading" id="h-breathtaking-pace-of-the-parker-solar-probe">Breathtaking pace of the Parker solar probe</h2>



The spacecraft is moving at approximately <a href="https://www.nasa.gov/feature/goddard/parker-solar-probe" target="_blank" rel="noreferrer noopener">430,000 miles per hour</a>. At that velocity, Parker could zip from New York to Los Angeles in about 20 seconds. 



By <a href="https://www.earth.com/news/parker-solar-probe-will-fly-through-suns-atmosphere-tomorrow-for-the-first-time/" target="_blank" rel="noreferrer noopener">approaching the Sun</a> so closely, mission teams hope to retrieve data that no earlier craft could access. Particles in the corona -- where temperatures can exceed a few million degrees -- tend to behave in puzzling ways. 



Scientists aim to see how these intense conditions might shape <a href="https://science.nasa.gov/sun/what-is-the-solar-wind/" target="_blank" rel="noreferrer noopener">solar wind</a>, which jets out at more than one million miles per hour.



Engineers designed Parker’s trajectory with careful flybys of Venus to shrink its orbit gradually around the Sun. This path has taken years to perfect since launch in 2018. 



Each loop demanded detailed calculations to ensure the craft can survive the approach, collect the right measurements, and keep sending updates back to Earth.



<h2 class="wp-block-heading" id="h-solar-probe-battling-extreme-heat">Solar probe battling extreme heat</h2>



Because the Sun’s heat is punishing at such a short distance, Parker Solar Probe relies on a <a href="https://parkersolarprobe.jhuapl.edu/Spacecraft/index.php#Extreme-Environments" target="_blank" rel="noreferrer noopener">carbon-composite shield</a> 4.5 inches thick.



This protective layer keeps sensitive instruments near room temperature while the shield’s front side can face extreme temperatures above 2,500 degrees Fahrenheit.



Sophisticated cooling systems also channel heat away from the core of the <a href="https://www.earth.com/news/meet-the-fastest-human-made-object-ever-nasas-parker-solar-probe/" target="_blank" rel="noreferrer noopener">spacecraft</a>, helping to sustain the electronics that record measurements of plasma, magnetic fields, and solar wind particles.



Inside, the instruments are scanning for clues to explain the corona’s unusual temperatures, which skyrocket to levels far higher than the Sun’s visible surface. 



Those same instruments are also watching for charged particle bursts and fluctuations in magnetic fields that might help answer big questions about what accelerates the solar wind.



<h2 class="wp-block-heading" id="h-crucial-timing-and-limited-contact">Crucial timing and limited contact</h2>



Today’s perihelion means Parker is currently skimming the outer atmosphere of the <a href="https://www.earth.com/news/solar-orbiter-spacecraft-sees-the-sun-through-three-different-lenses/" target="_blank" rel="noreferrer noopener">Sun</a> while in autonomous mode, out of immediate radio contact.



This window of silence is standard because powerful solar emissions prevent reliable communication. Mission operators anticipate a beacon tone on December 27, which should confirm Parker has survived.



Scientists believe that data from this flyby could provide <a href="https://www.earth.com/news/parker-solar-probe-will-fly-through-suns-atmosphere-tomorrow-for-the-first-time/" target="_blank" rel="noreferrer noopener">unprecedented detail on solar activity</a>. Periods of heightened activity, known as solar maxima, produce more flares and coronal mass ejections. These events can spawn auroras at unexpected latitudes and threaten satellites with bursts of charged particles. 



By collecting data from close range, Parker might reveal new insights into how these explosive happenings form and evolve.



<h2 class="wp-block-heading" id="h-visionary-behind-the-parker-solar-probe">Visionary behind the Parker solar probe</h2>



This trailblazer of solar research is named after <a href="https://news.uchicago.edu/story/eugene-parker-legendary-figure-solar-science-and-namesake-parker-solar-probe-1927-2022" target="_blank" rel="noreferrer noopener">Dr. Eugene N. Parker</a>, the late astrophysicist from the University of Chicago who proposed the existence of the solar wind back in the 1950s.



He changed our understanding of how stars interact with their surroundings. In 2018, he became the first person to witness the launch of a spacecraft bearing his name. 



Though he passed away in 2022, his legacy lives on in every close pass the probe completes.



<h2 class="wp-block-heading" id="h-a-closer-look-at-solar-wind">A closer look at solar wind</h2>



One of the main motivations behind Parker Solar Probe mission is to figure out how <a href="https://www.earth.com/news/strong-solar-storm-warning-issued-as-two-cmes-will-hit-earth-tomorrow/" target="_blank" rel="noreferrer noopener">solar wind</a>, that stream of charged particles racing from the Sun, accelerates to incredible speeds. Scientists hope Parker will pinpoint where and how energy is transferred to these particles. Such information could refine space weather forecasts, which are critical for protecting satellites, power grids, and astronauts in orbit.



<a href="https://www.plasmacoalition.org/plasma_writeups/solar_plasmas.pdf" target="_blank" rel="noreferrer noopener">Plasma</a> behavior at these altitudes can also inform theories about stellar physics beyond the Sun. 



Many stars release similar particle streams, so unraveling the inner workings of the solar wind could offer a template for understanding events happening light-years away.



<h2 class="wp-block-heading" id="h-high-stakes-data-for-space-weather-predictions">High-stakes data for space weather predictions</h2>



Operators know that space weather can have major effects here on Earth. Sudden geomagnetic storms have been known to disrupt radio signals, damage satellites, and even cause power outages. By studying the Sun’s activity from the inside, Parker could lead to more accurate warnings for regions of the world vulnerable to blackouts. 



Air traffic, GPS services, and communication infrastructure may all benefit from improved predictions of <a href="https://science.nasa.gov/science-research/heliophysics/space-weather/solar-flares/what-is-a-solar-flare/" target="_blank" rel="noreferrer noopener">solar flares</a> and <a href="https://www.swpc.noaa.gov/phenomena/solar-radiation-storm#:~:text=Solar%20radiation%20storms%20occur%20when,of%20the%20speed%20of%20light." target="_blank" rel="noreferrer noopener">particle storms</a>.



<h2 class="wp-block-heading" id="h-a-milestone-for-parker-solar-probe">A milestone for Parker Solar Probe</h2>



Now that the probe is at perihelion, mission managers will hold their breath for a few days.



“No human-made object has ever passed this close to a star, so Parker will truly be returning data from uncharted territory,” explained <a href="https://parkersolarprobe.jhuapl.edu/News-Center/Show-Article.php?articleID=205" target="_blank" rel="noreferrer noopener">Nick Pinkine</a>, Parker Solar Probe mission operations manager at <a href="https://www.jhuapl.edu/" target="_blank" rel="noreferrer noopener">APL</a>. 



He added that the team is eager to see how Parker managed the flyby when the link reopens.



This moment is a milestone for solar science. If everything goes as planned, Parker will maintain its orbit for future close passes, each offering a renewed chance to investigate the corona’s strange properties.



Researchers anticipate more discoveries that will fill in knowledge gaps about the Sun’s extreme environment.



Far from being an isolated phenomenon, the Sun’s behavior plays a significant role in shaping conditions on Earth. 



Today’s brush with solar fury signals the continuing progress of human exploration -- and the promise of deeper insight into the star that illuminates our world.



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Solar Probe touched the Sun, now scientists wait for a signal and "proof of life"

NASA’s Parker Solar Probe touched the Sun's atmosphere, flying within...

Scientists have long looked to oxygen when searching for signs of life beyond Earth. This gas sustains breathing and enables animals and plants to flourish. Now, researchers suggest that oxygen might also point to advanced technology. 



If an exoplanet’s atmosphere holds enough oxygen, it may not only support organisms but also help them spark fire, build structures, and craft machinery.



A study in Nature Astronomy presents this view, highlighting oxygen’s value as more than just a sign of biology. 



<h2 class="wp-block-heading" id="h-oxygen-civilization-and-technology">Oxygen, civilization, and technology</h2>



Leading this research are <a href="https://www.pas.rochester.edu/people/faculty/frank_adam/index.html" target="_blank" rel="noreferrer noopener">Adam Frank</a>, the Helen F. and Fred H. Gowen Professor of Physics and Astronomy at the University of Rochester, and <a href="https://www-en.fisica.uniroma2.it/phone-directory/balbia_en/" target="_blank" rel="noreferrer noopener">Amedeo Balbi</a>, an associate professor of astronomy and astrophysics at the University of Roma Tor Vergata, Italy.



Together with their team, they set out to explore whether oxygen is a key factor in allowing extraterrestrial civilizations to emerge and thrive through the development of technology.



“We are ready to find signatures of life on alien worlds,” Frank says. “But how do the [oxygen] conditions on a planet tell us about the possibilities for intelligent, technology-producing life?” 



This question drives efforts to examine oxygen’s role beyond respiration and metabolism, especially in relation to large-scale industrial activities.



<h2 class="wp-block-heading" id="h-why-oxygen-matters-for-civilizations">Why oxygen matters for civilizations</h2>



<a href="https://www.earth.com/news/animal-cells-capable-of-photosynthesis-created-for-the-first-time/" target="_blank" rel="noreferrer noopener">Photosynthesis</a> on Earth accounts for the bulk of our oxygen on our planet, thanks to countless organisms that use sunlight to make food. 



Because this process produces so much oxygen, it has been considered a biosignature. A planet with significant oxygen levels hints that life may be present, but Frank and Balbi argue that oxygen also has a second function.



“<a href="https://www.nature.com/articles/s41550-023-02112-8" target="_blank" rel="noreferrer noopener">In our paper</a>, we explore whether any atmospheric composition would be compatible with the presence of advanced technology,” Balbi says. “We found that the atmospheric requirements may be quite stringent.”



The link to technology comes from open-air combustion. Smelting metals, cooking food, and powering engines all rely on oxygen. 



Any alien civilization that forges metals would need a certain percentage of oxygen in its air to keep fires burning reliably. That percentage, according to Earth’s history, appears to be around 18 percent.



<h2 class="wp-block-heading" id="h-fire-and-the-18-threshold">Fire and the 18% threshold</h2>



“You might be able to get biology -- you might even be able to get intelligent creatures -- in a world that doesn’t have oxygen,” Frank says, “but without a ready source of fire, you’re never going to develop higher technology because higher technology requires fuel and melting.” 



He calls attention to fire’s role in shaping tools, infrastructure, and <a href="https://www.earth.com/news/human-wellbeing-is-a-more-effective-focus-area-when-discussing-energy-solutions/" target="_blank" rel="noreferrer noopener">energy production</a>. Metalworking, for instance, depends on sustaining flames hot enough to melt ore and craft refined structures.



Frank and Balbi refer to this requirement as an “oxygen bottleneck.” A planet might host life forms of various kinds, yet remain stuck without the combustion needed to fuel industrial breakthroughs. 



“The presence of high degrees of oxygen in the atmosphere is like a bottleneck you have to get through in order to have a technological species,” Frank says. 



“You can have everything else work out, but if you don’t have <a href="https://www.earth.com/news/it-took-200-million-years-for-earth-to-get-its-oxygen/" target="_blank" rel="noreferrer noopener">oxygen in the atmosphere</a>, you’re not going to have a technological species.”



<h2 class="wp-block-heading" id="h-oxygen-technology-create-technosignatures">Oxygen + technology create "technosignatures"</h2>



Frank thinks that exoplanets with oxygen levels at or above 18 percent should be at the top of our search list. 



“Targeting planets with high oxygen levels should be prioritized because the presence or absence of high oxygen levels in exoplanet atmospheres could be a major clue in finding potential technosignatures,” Frank says. 



Planets that exceed this level may have the capacity for factories, infrastructure, or communication networks.



Balbi notes that interpreting any possible signal of intelligent life will be challenging. 



“The implications of discovering intelligent, technological life on another planet would be huge,” adds Balbi. “Therefore, we need to be extremely cautious in interpreting possible detections. 



Their study suggests that astronomers should be skeptical of potential technosignatures from a planet with insufficient <a href="https://www.earth.com/news/earths-ancient-breath-study-links-atmospheric-oxygen-and-mantle-chemistry/" target="_blank" rel="noreferrer noopener">atmospheric oxygen</a>.



<h2 class="wp-block-heading" id="h-technosphere-vs-biotechnosphere">Technosphere vs. biotechnosphere</h2>



Frank and Balbi’s perspective also covers the idea of a technosphere, which is the collective output of an advanced civilization. 



Factories, vehicles, and power grids all fit under this label. They rely on resources provided by the planet’s biosphere but stretch beyond purely natural processes. 



<a href="https://www.earth.com/news/bronze-age-technology-is-a-modern-solution-for-clean-energy/" target="_blank" rel="noreferrer noopener">Burning fuels in open air</a> has been central to every major industrial leap, from forging steel to generating electricity.



When these technologies reach a global scale, they form a biotechnosphere. This term applies to the interplay of living systems and technology -- essentially, how organisms and machines coexist. 



On Earth, that includes everything from smartphones to farms, all running side by side. A well-established biotechnosphere might produce clear signals in the atmosphere: waste gases, <a href="https://www.earth.com/news/mapping-2024s-record-heat-unveiling-earths-climate-danger-zones/" target="_blank" rel="noreferrer noopener">unusual heat patterns</a>, or <a href="https://www.earth.com/news/forever-chemicals-found-in-tap-and-bottled-water-worldwide/" target="_blank" rel="noreferrer noopener">chemicals not normally found in nature</a>.



<h2 class="wp-block-heading" id="h-balancing-machines-and-ecosystems">Balancing machines and ecosystems</h2>



History shows that as technology expands, it can sometimes damage or alter environments. Factories might pump pollutants into the air, while deforestation removes habitats that produce oxygen. 



Yet there is an ongoing move toward cleaner energy and more efficient resource use. If any alien civilization follows a similar path, we might detect certain byproducts in the form of <a href="https://www.earth.com/news/2023-climate-change-report-record-high-temperatures-greenhouse-gases-sea-level-rise/" target="_blank" rel="noreferrer noopener">greenhouse gases</a> or <a href="https://www.earth.com/news/banning-forever-chemicals-may-threaten-us-national-security/" target="_blank" rel="noreferrer noopener">engineered molecules</a>.



Though the focus is on oxygen, other factors matter too, such as temperature and access to metals or fuels. A planet may need stable conditions for life to progress to a point where industry becomes possible.



That said, Frank and Balbi’s findings highlight how oxygen stands out among these factors, because it directly enables combustion processes.



<h2 class="wp-block-heading" id="h-fire-and-progress-in-earth-s-past">Fire and progress in Earth’s past</h2>



Earth’s own development through advances in technology offers insight into how vital oxygen has been for technical achievements.



Once our atmosphere had enough of it, humans learned to manipulate fire for cooking and for <a href="https://www.earth.com/news/worlds-oldest-wooden-structure-completely-rewrites-early-human-history/" target="_blank" rel="noreferrer noopener">making stronger materials</a>. 



From simple smithing to modern manufacturing, every stage of growth involved open-air combustion.



“You can have everything else work out, but if you don’t have oxygen in the atmosphere, you’re not going to have a technological species,” Frank says. 



This idea underlines how a single factor -- oxygen -- can open or close the door to industrial progress, altering a <a href="https://www.earth.com/news/decarbonizing-worlds-industrial-emissions-possible-with-current-technology/" target="_blank" rel="noreferrer noopener">planet’s entire future path</a>.



<h2 class="wp-block-heading" id="h-oxygen-technology-and-next-steps">Oxygen, technology, and next steps</h2>



Observatories now in the works may soon gather data about exoplanet atmospheres in detail. Detecting a high oxygen content could mark a world that supports advanced living organisms. 



The next task is to look for proof of industry or technology, sometimes called technosignatures. These might appear as chemical emissions, <a href="https://www.earth.com/news/deep-space-radio-signal-reaches-earth-after-8-billion-years-frb-20220610a/" target="_blank" rel="noreferrer noopener">radio signals</a>, or specific spectral lines.



If these two checks-- oxygen above 18 percent and evidence of artificial activity -- both yield results, we will have a strong indication that we share the universe with another technological civilization. 



That reality could reshape how we see ourselves and our place among the stars.



<h2 class="wp-block-heading" id="h-why-does-any-of-this-matter-0">Why does any of this matter?</h2>



Understanding the significance of atmospheric oxygen can also inspire reflection on our home planet. Human industries <a href="https://www.earth.com/news/air-pollution-from-fossil-fuels-kills-5-million-people-each-year/" target="_blank" rel="noreferrer noopener">rely heavily on combustion</a>, from running cars to powering factories. This has changed Earth’s ecosystems. 



As we learn more about how oxygen in an atmosphere enables or limits technology, we might gain new ideas on how to manage our own balance between growth and <a href="https://www.earth.com/news/un-report-calls-for-global-change-to-stop-biodiversity-loss/" target="_blank" rel="noreferrer noopener">environmental health</a>.



Ultimately, Frank and Balbi’s argument shows that oxygen may do far more than keep living cells alive. It might be the clearest signal of whether a planet can support the technologies that shape modern societies. 



By recognizing the 18 percent threshold, scientists can refine their search for advanced life and possibly move closer to answering the age-old question: Are we alone, or is someone else using fire to reshape their world?



The full study was published in the journal <a href="https://www.nature.com/articles/s41550-023-02112-8" target="_blank" rel="noreferrer noopener">Nature Astronomy</a>.



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Oxygen levels on exoplanets reveal presence of alien technology

Scientists have long looked to oxygen when searching for signs...

Picture a landscape on Mars where frost covers the ground, and the crisp sound of icy surfaces breaking underfoot fills the air. Above, sunlight filters through clouds mixed with ice and dust, creating a warm, golden glow. This is the Australe Scopuli region, located at the southern pole of Mars.



It offers a striking contrast - its alien features are shaped by the Red Planet's unique environment, yet its serene beauty evokes scenes that feel almost Earth-like.



This blend of the otherworldly and the familiar makes it a captivating subject for scientific exploration and visual fascination.



<h2 class="wp-block-heading" id="h-australe-scopuli-unique-polar-landscape-on-mars">Australe Scopuli: Unique polar landscape on Mars</h2>



The High Resolution Stereo Camera (HRSC) aboard the&nbsp;<a href="https://www.esa.int/Science_Exploration/Space_Science/Mars_Express" target="_blank" rel="noreferrer noopener">Mars Express</a>&nbsp;captured stunning images of Australe Scopuli, displaying its distinctive polar deposits.



This region lies near the "cryptic terrain," a puzzling area previously explored by few scientists. Here, layers of carbon dioxide ice and dust swirl together, creating a white, frosty terrain that contrasts sharply with the iconic red <a href="https://www.earth.com/news/how-mars-became-uninhabitable-after-being-life-supporting-ocean-world/" target="_blank" rel="noreferrer noopener">Martian soil</a>.



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2024/12/mars_south-pole_Australe-Scopuli-region_frost_ice_Mars-Express_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2024/12/mars_south-pole_Australe-Scopuli-region_frost_ice_Mars-Express_1s.webp" alt="Swirls of light and dark layers mark the boundaries between ice and dust layers exposed in this icy scene from the Australe Scopuli region of Mars. The right side of the image has a lot of ice coverage compared with the left hand side that has numerous dark fan-shaped deposits tracing the horizontal layers. Credit: Mars Express/ESA" class="wp-image-1954353"/></a><figcaption class="wp-element-caption">Swirls of light and dark layers mark the boundaries between ice and dust layers exposed in this icy scene from the Australe Scopuli region of Mars. The right side of the image has a lot of ice coverage compared with the left hand side that has numerous dark fan-shaped deposits tracing the horizontal layers. Credit: Mars Express/ESA</figcaption></figure>



These layered polar deposits result from seasonal cycles, with ice forming and trapping varying amounts of dust. 



The contrasting light and dark layers are particularly visible on hills and in valleys, painting the landscape with striking textures.



When viewed through 3D glasses, the region’s topography resembles Earthly ski resorts, with smooth slopes, sharp turns, and steep hillsides.



But skiing on Mars would require preparation for extreme cold: temperatures here plunge to a bone-chilling -125°C (-193°F).



<h2 class="wp-block-heading" id="h-changing-seasons-and-martian-spiders">Changing seasons and Martian "spiders"</h2>



The images, taken on June 16, 2022, during the <a href="https://www.earth.com/news/hidden-water-found-on-mars-would-cover-the-planet-over-one-mile-deep/" target="_blank" rel="noreferrer noopener">Martian</a> summer solstice, showcase how Mars’s southern pole transitions with the changing seasons.



Dark patches in the imagery reveal areas where carbon dioxide ice has sublimated, a process where the ice turns directly from solid to vapor without melting.



This sublimation is driven by sunlight, which warms the ice. As the ice evaporates, it leaves behind trails of dark dust spread across the surface. 



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2024/12/mars_south-pole_Australe-Scopuli-region_perspective_Mars-Express_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2024/12/mars_south-pole_Australe-Scopuli-region_perspective_Mars-Express_1s.webp" alt="Perspective view across undulating terrain at the Australe Scopuli region of Mars, with exposed layers of ice and dust. Numerous dark dusty fan-shaped features follow the pattern of the layers. Credit: Mars Express/ESA" class="wp-image-1954355"/></a><figcaption class="wp-element-caption">Perspective view across undulating terrain at the Australe Scopuli region of Mars, with exposed layers of ice and dust. Numerous dark dusty fan-shaped features follow the pattern of the layers. Credit: Mars Express/ESA</figcaption></figure>



These fan-shaped patterns, sculpted by prevailing winds, provide a remarkable look at the seasonal dynamics in <a href="https://www.earth.com/news/mars-gravity-pulls-earth-closer-to-the-sun-warming-our-climate-scientists-say/" target="_blank" rel="noreferrer noopener">Mars</a>'s polar regions.



As summer progresses, sunlight penetrates the translucent carbon dioxide ice, heating the ground beneath it. This leads to the formation of gas pockets as the underlying ice sublimates. 



When the gas pressure becomes too high, the ice cracks, releasing bursts of gas and dust into the atmosphere. These jets create fan-shaped deposits that can stretch for hundreds of meters.



This process resembles the formation of <a href="https://www.earth.com/news/marss-space-debris-should-be-regarded-as-historical-artifacts/" target="_blank" rel="noreferrer noopener">Martian</a> "spiders," another fascinating feature observed in recent&nbsp;Mars Express imagery, where similar sublimation mechanisms create spider-like patterns on the surface.



<h2 class="wp-block-heading" id="h-dynamic-australe-scopuli-of-mars">Dynamic Australe Scopuli of Mars</h2>



A detailed look at Australe Scopuli shows that the dust jets typically emerge along the edges of layered polar deposits. These boundaries may act as fragile zones, allowing the jets to break through with less resistance.



This phenomenon, shaped by seasonal temperature changes and the region’s topography, creates a dynamic and evolving <a href="https://www.earth.com/news/air-samples-from-mars-could-reveal-fascinating-secrets/" target="_blank" rel="noreferrer noopener">Martian</a> landscape. 



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2024/12/mars_south-pole_Australe-Scopuli-region_topography_Mars-Express_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2024/12/mars_south-pole_Australe-Scopuli-region_topography_Mars-Express_1s.webp" alt="A topography map of Australe Scopuli region of Mars color-coded according to relative heights. The scale goes from red (highest terrain) through yellow, green, blue and purple (lowest terrain). Credit: Mars Express/ESA" class="wp-image-1954357"/></a><figcaption class="wp-element-caption">A topography map of Australe Scopuli region of Mars color-coded according to relative heights. The scale goes from red (highest terrain) through yellow, green, blue and purple (lowest terrain). Credit: Mars Express/ESA</figcaption></figure>



The interplay between the shifting ice and dust patterns highlights the complexity of Mars’s natural processes.



Although building a snowman on Mars might not be possible, the Australe Scopuli region captures the essence of the planet’s unique beauty. 



It offers scientists and explorers a fascinating glimpse into the changing polar environment of the Red Planet.



<h2 class="wp-block-heading" id="h-science-behind-the-images">Science behind the images</h2>



The HRSC on&nbsp;Mars Express&nbsp;is a remarkable piece of engineering, designed and developed by the German Aerospace Center (DLR).



After the camera captured detailed images of Mars, the <a href="https://www.dlr.de/en/pf/about-us/departments" target="_blank" rel="noreferrer noopener">DLR Institute for Planetary Research</a> in Berlin-Adlershof processed the data. 



Using this data, the Planetary Science and Remote Sensing group at <a href="https://www.fu-berlin.de/en/index.html" target="_blank" rel="noreferrer noopener">Freie Universität Berlin</a> created the stunning final images we see today.



In conclusion, the images of Australe Scopuli offer much more than just stunning visuals of the Martian southern pole. 



They serve as powerful proof of the intricate and ever-changing processes that sculpt the Red Planet's icy polar regions.



Every layer of ice and dust preserved in these photographs tells a unique story about <a href="https://www.earth.com/news/mars-curiosity-rover-makes-surprising-find-under-martian-rock-sulfur-crystals/" target="_blank" rel="noreferrer noopener">Mars</a>'s geological and climatic history. 



By studying these features in detail, researchers can piece together the planet's evolving climate and uncover the mysteries of its geological past.



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White Christmas on Mars with its changing polar landscapes

Picture a landscape on Mars where frost covers the ground,...

Geometry,Of,Space,Series.,Backdrop,Of,Conceptual,Grids,,Curves,And

Dark energy has long been seen as the invisible force behind our Universe’s accelerating expansion. This mysterious component was thought to make up nearly 70 percent of the cosmic energy budget. A new study, however, raises a different idea: maybe the Universe is expanding in a “lumpy” manner, which means dark energy might not be needed to explain those puzzling measurements of distant supernovae.



<h2 class="wp-block-heading" id="h-dark-energy-and-expansion">Dark energy and expansion</h2>



For almost a century, scientists have assumed that the <a href="https://www.earth.com/news/new-evidence-suggests-that-dark-energy-comes-from-black-holes/" target="_blank" rel="noreferrer noopener">cosmos</a> spreads out uniformly in every direction, with dark energy speeding up that expansion. The notion was adopted after researchers saw exploding stars, known as supernovae, appearing farther away than expected. 



When calculations showed that galaxies seemed to be drifting apart too quickly, dark energy became an easy placeholder for the unknown physics.



Professor <a href="https://profiles.canterbury.ac.nz/David-Wiltshire" target="_blank" rel="noreferrer noopener">David Wiltshire</a> from the <a href="https://www.canterbury.ac.nz/" target="_blank" rel="noreferrer noopener">University of Canterbury</a> in Christchurch, New Zealand has been examining this challenge in more detail. 



His research team’s <a href="https://academic.oup.com/mnrasl/article/537/1/L55/7926647" target="_blank" rel="noreferrer noopener">analysis</a> of supernova light curves suggests the <a href="https://www.earth.com/news/mapping-the-universe-may-reveal-secrets-of-dark-energy/" target="_blank" rel="noreferrer noopener">Universe</a> may be more uneven than we assumed.



Their approach leads to a fresh explanation for the changes in light we see, one that focuses on how time passes differently in various gravitational conditions rather than appealing to an unseen substance.



<h2 class="wp-block-heading" id="h-why-many-have-relied-on-dark-energy">Why many have relied on dark energy</h2>



Dark energy has been tied to the so-called Lambda Cold Dark Matter model, or <a href="https://lambda.gsfc.nasa.gov/education/graphic_history/univ_evol.html" target="_blank" rel="noreferrer noopener">ΛCDM model</a>. 



This model has served as the bedrock of modern cosmology for decades. Scientists had no direct means to detect or measure dark energy, so they relied on the <a href="https://iopscience.iop.org/article/10.3847/1538-4357/aca5fa" target="_blank" rel="noreferrer noopener">apparent acceleration</a> seen in distant supernovae. They also looked to patterns in the <a href="https://www.esa.int/Science_Exploration/Space_Science/Cosmic_Microwave_Background_CMB_radiation" target="_blank" rel="noreferrer noopener">Cosmic Microwave Background</a>, which is often described as the faint afterglow of the Big Bang. 



Over the years, more data have hinted that there could be tension between early and recent <a href="https://www.earth.com/news/dark-energy-could-explain-the-rapid-expansion-of-the-early-universe/" target="_blank" rel="noreferrer noopener">expansion</a> rates, sparking serious questions about whether we are missing some major puzzle piece.



<h2 class="wp-block-heading" id="h-enter-the-timescape-model">Enter the timescape model</h2>



The new work supports something called the timescape model, which does not need dark energy to explain cosmic acceleration. Instead, it notes that local physics can vary depending on how mass is distributed. One clock drifting through a sparse region of the cosmos might tick faster than the same clock inside a galaxy packed with more gravitational pull. 



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2024/12/dark-energy_doesnt-exist_history-of-universe-graphic_credit-NASA_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2024/12/dark-energy_doesnt-exist_history-of-universe-graphic_credit-NASA_1s.webp" alt="This graphic offers a glimpse of the history of the universe, as we currently understand it. The cosmos began expanding with the Big Bang but then around 10 billion years later it strangely began to accelerate thanks to a theoretical phenomenon termed dark energy. Credit: NASA" class="wp-image-1954661"/></a><figcaption class="wp-element-caption">This graphic offers a glimpse of the history of the universe, as we currently understand it. The cosmos began expanding with the Big Bang but then around 10 billion years later it strangely began to accelerate thanks to a theoretical phenomenon termed dark energy. Credit: NASA</figcaption></figure>



The team’s findings were featured in the journal Monthly Notices of the Royal Astronomical Society Letters.



“Our findings show that we do not need dark energy to explain why the <a href="https://www.earth.com/news/study-dark-matter-does-not-exist-and-the-universe-is-27-billion-years-old/" target="_blank" rel="noreferrer noopener">Universe</a> appears to expand at an accelerating rate,” noted Professor David Wiltshire, who led the study. 



He sees this approach as an opportunity to rethink the way we average cosmic expansion. “The Universe’s biggest mystery could be settled by the end of the decade,” Professor Wiltshire claimed.



<h2 class="wp-block-heading" id="h-hubble-tension-and-the-lumpy-universe">Hubble tension and the lumpy Universe</h2>



Part of the growing dispute involves something called the <a href="https://www.earth.com/news/unknown-factors-are-accelerating-the-expansion-of-the-universe/" target="_blank" rel="noreferrer noopener">Hubble tension</a>.



<a href="https://www.aanda.org/articles/aa/full_html/2020/09/aa33910-18/aa33910-18.html" target="_blank" rel="noreferrer noopener">Measurements</a> of the early cosmos from the Cosmic Microwave Background suggest a certain rate of expansion, while observations of supernovae in the present day reveal a faster pace. This inconsistency has triggered re-examinations of old assumptions. Adding to that, the Dark Energy Spectroscopic Instrument (<a href="https://iopscience.iop.org/article/10.3847/1538-4357/aca5fa" target="_blank" rel="noreferrer noopener">DESI</a>) has discovered that the standard ΛCDM model may not line up perfectly with some of its new high-precision data. Researchers are looking into models where dark energy <a href="https://www.earth.com/news/dark-energy-is-ripping-the-universe-apart-but-we-arent-sure-how/" target="_blank" rel="noreferrer noopener">might change over time</a>, but the timescape idea takes a different path: it challenges the uniformity assumption at its core.



<h2 class="wp-block-heading" id="h-rethinking-dark-energy">Rethinking dark energy </h2>



If the Universe is lumpy, with matter clumping in some regions and emptier voids in others, then local gravitational effects might skew the calculations that gave dark energy its place in cosmic theory. <a href="https://www.astro.uvic.ca/~jwillis/teaching/astr405/astr405_lecture6.pdf?utm_blank" target="_blank" rel="noreferrer noopener">Traditional equations</a> used to describe expansion were first introduced almost a hundred years ago, so some researchers argue that the Universe’s complex structures were overlooked. This new study insists that a <a href="https://www.earth.com/news/universe-expansion-rate-dark-energy-measured-11-billion-years-ago/" target="_blank" rel="noreferrer noopener">uniform expansion</a> might not be the full story. When you allow for different gravitational influences, dark energy becomes optional.



<h2 class="wp-block-heading" id="h-looking-ahead-to-fresh-data">Looking ahead to fresh data</h2>



Several upcoming projects are on the horizon. 



The European Space Agency’s <a href="https://www.esa.int/Science_Exploration/Space_Science/Euclid" target="_blank" rel="noreferrer noopener">Euclid</a> satellite launched in July 2023, and future missions like the <a href="https://science.nasa.gov/mission/roman-space-telescope/" target="_blank" rel="noreferrer noopener">Nancy Grace Roman Space Telescope</a> promise more comprehensive observations of supernovae. The timescape team believes that at least 1,000 high-quality supernova measurements could be enough to show if their approach really works. 



If timescape ideas pass these tests, the so-called “biggest mystery” might get resolved sooner than people think.



<h2 class="wp-block-heading" id="h-what-does-all-of-this-mean">What does all of this mean?</h2>



To sum it all up, the Universe is more intricate than any simple map might reveal. If the <a href="https://ui.adsabs.harvard.edu/abs/2011MNRAS.413..367S/abstract" target="_blank" rel="noreferrer noopener">timescape model</a> holds up under further scrutiny, there could be wide-ranging effects on cosmic models, especially those that rely on dark energy as a key ingredient. Astronomers, physicists, and cosmologists will be watching closely as more data come in from cutting-edge surveys and instruments. 



These results might bring clarity to the <a href="https://www.earth.com/news/dark-energy-could-explain-the-rapid-expansion-of-the-early-universe/" target="_blank" rel="noreferrer noopener">Hubble tension</a> or uncover new clues about the structure and history of everything around us.



Dark energy has been the leading explanation for cosmic acceleration for decades. Yet, if local gravitational differences and variable clock speeds can account for what we see, the door may be open to a more nuanced story of cosmic growth. There is no shortage of skepticism within the scientific community, but unexpected solutions to old puzzles are often how we expand our understanding of the Universe. 



If the timescape approach stands the test of fresh observations, future textbooks might look a little different.



The full study is published in the <a href="https://academic.oup.com/mnrasl/article/537/1/L55/7926647" target="_blank" rel="noreferrer noopener">Monthly Notices of the Royal Astronomical Society: Letters</a>.



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Wrong again? Dark energy doesn't exist and the universe is "lumpy"

Dark energy has long been seen as the invisible force...

NASA's Perseverance rover has recently completed a significant part of its arduous journey on the Martian surface.



Aptly named "Lookout Hill," it's the apex of the Jezero Crater's rim - a location that is noteworthy due to the unique form of Martian geology it presents.



This milestone marks the conclusion of the uphill adventure, a process that has lasted more than three months and has seen the rover maneuver its way up 1,640 vertical feet (500 vertical meters) with an incline of 20 percent. 



The rover diligently recorded observations at stops along the way.



<div class="wp-block-sendtonews-playerselector">[sendtonews key="5xPIlWSDKm-4160431-12187" type="single"]</div>



<h2 class="wp-block-heading" id="h-perseverance-conquers-the-jezero-crater-rim">Perseverance conquers the Jezero Crater rim</h2>



The exploration of Lookout Hill was recently discussed in a media briefing at the American Geophysical Union’s annual meeting - the largest gathering of Earth and space scientists in the country. The experts noted that the path to Lookout Hill was challenging.



"During the <a href="https://www.earth.com/news/lake-sediments-found-in-jezero-crater-hint-at-past-life-on-mars/" target="_blank" rel="noreferrer noopener">Jezero Crater</a> rim climb, our rover drivers have done an amazing job negotiating some of the toughest terrain we’ve encountered since landing,” explained Steven Lee, deputy project manager for Perseverance. 



As innovative approaches were invented and tested, like trying to move backward, the rover successfully navigated these difficulties and survived like a true champion. 



<h2 class="wp-block-heading" id="h-the-ongoing-work-of-perseverance">The ongoing work of Perseverance </h2>



The journey is not over yet. The science team has more to uncover in the next phase of the campaign.



Since its arrival at Jezero in February 2021, Perseverance has accomplished four science campaigns: the “Crater Floor,” “Fan Front,” “Upper Fan,” and “Margin Unit.” 



Now, as it commences its 5th <a href="https://www.earth.com/news/perseverance-rover-begins-steep-climb-up-martian-crater-rim-jezero-crater/" target="_blank" rel="noreferrer noopener">campaign</a>, named the “Northern Rim,” it is expected to visit up to four sites of geological interest, gather samples, and cover about four miles (6.4 kilometers).



“The Northern Rim campaign brings us completely new scientific riches as Perseverance roves into fundamentally new geology,” noted Ken Farley, project scientist for Perseverance.



This expedition signifies a shift from studying rocks, which partially filled the Jezero Crater upon its formation, to examining rocks thrown up from deep within the <a href="https://www.earth.com/news/nasas-curiosity-rover-records-a-martian-day-from-dawn-to-dusk/" target="_blank" rel="noreferrer noopener">Martian</a> crust due to the impact. 



These ancient rocks hold clues to the planet's early history and may offer insights into Earth's formative years.



<h2 class="wp-block-heading" id="h-the-first-landmark-witch-hazel-hill">The first landmark: Witch Hazel Hill</h2>



After the triumph on Lookout Hill, Perseverance embarked on its quest to unearth the Martian history encoded in the layered outcrop of a geological feature known as "Witch Hazel Hill."



"Each layer is like a page in the book of Martian history," explained Candice Bedford, a scientist associated with the Perseverance project.



As the rover descends the hill, it will explore deeper into the ancient Martian environments recorded in the crater rim.



After descending, the journey continues toward "Lac de Charmes," a location about 2 miles south, which is situated on the plains beyond the rim. This region is less likely to be significantly affected by the formation of Jezero Crater.



Following its trip to Lac de Charmes, the <a href="https://www.earth.com/news/perseverance-rover-finds-best-evidence-yet-life-on-mars-cheyava-falls-rock/" target="_blank" rel="noreferrer noopener">rover</a> will to explore an impressive outcrop of large blocks known as megabreccia.



These blocks could reveal ancient bedrock that was shattered during the Isidis impact - an event that presumably gouged deeply into the Martian crust and created a wide impact basin.



<h2 class="wp-block-heading" id="h-the-primary-mission-of-perseverance">The primary mission of Perseverance </h2>



A crucial part of Perseverance's mission is the pursuit of astrobiology, which includes finding samples that may bear signs of ancient microbial life. 



The rover will analyze the Red Planet’s geology and previous climate patterns to aid future human expeditions to <a href="https://www.earth.com/news/the-search-for-signs-of-life-on-mars-continues/" target="_blank" rel="noreferrer noopener">Mars</a>. The mission also includes the collection and caching of Martian rock and regolith.



As a part of NASA’s Moon to Mars exploration approach, the Mars 2020 Perseverance mission collaborates with ESA (European Space Agency) in the Mars Sample Return Program. 



The fundamental goal of this program is to collect sealed samples from the Martian surface and return them to Earth for detailed analysis.



The operations of the rover are all managed by <a href="https://www.jpl.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA’s Jet Propulsion Laboratory</a>, which is operated by Caltech on behalf of the agency.



The information in this article is sourced from <a href="https://www.jpl.nasa.gov/news/nasas-perseverance-rover-reaches-top-of-jezero-crater-rim/">NASA's JPL</a>.



Image Credit: NASA/JPL-Caltech/MSSS/JHU-APL



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Perseverance rover made an epic climb up the side of a crater

NASA's Perseverance rover has recently completed a significant part of...

Every holiday season, Americans buy nearly 30 million live Christmas trees. Many households cherish the scent of pine that drifts through their halls. The fragrance, which is often described as crisp and woodsy, can set a cheerful tone. Yet there is much more to this refreshing aroma.



That <a href="https://www.earth.com/news/what-gives-pine-trees-fresh-scent/" target="_blank" rel="noreferrer noopener">fresh smell</a> comes from substances known as volatile organic compounds, or VOCs. These are airborne chemicals that can be released by a wide range of items inside a home.



Fresh paint, cleaning solutions, and newly purchased furniture all have distinct VOC profiles that contribute to the atmosphere we breathe.



<h2 class="wp-block-heading" id="h-research-and-its-driving-force">Research and its driving force</h2>



"Our nose is a good chemical sensor," said Dustin Poppendieck, an environmental engineer at the National Institute of Standards and Technology (NIST). 



"We know that these trees are emitting something, and the question then becomes: How big of a source is it? We wanted to explore which chemicals are emitted and how much, and to put that into the context of other sources of chemicals in a house."



In a recent study, he and his colleagues took a Douglas fir and enclosed it in a specialized chamber. The team wanted to gauge which compounds lingered and how they might shift in a controlled environment. They kept track of the emissions for 17 days to gather a clear picture.



<h2 class="wp-block-heading" id="h-vocs-in-the-home">VOCs in the home</h2>



VOCs appear in many <a href="https://www.earth.com/news/household-chemicals-linked-to-neurological-disorders/" target="_blank" rel="noreferrer noopener">household products </a>and activities. They come from cleaners, new carpeting, varnishes, personal care items, and similar sources. Some have a pleasant smell that appeals to people, while others cause throat irritation and watery eyes for those who are sensitive.



Many manufacturers now produce items with fewer VOCs, including paint labeled as low-emission. People are also more aware of how indoor air quality impacts overall well-being, so they weigh their choices when buying scented or chemical-based goods. Even simple habits, like regularly airing out rooms, can help manage exposure.



<h2 class="wp-block-heading" id="h-christmas-tree-in-a-chamber">Christmas tree in a chamber</h2>



In the experiment, the researchers placed a decorated tree inside a chamber designed to mimic typical indoor conditions. The lights switched on and off every 12 hours, outside air came in at a realistic pace, and the tree was watered each day.



A specialized instrument called proton-transfer reaction mass spectrometry tracked airborne compounds in real time. This method offers a detailed look at changing levels of chemicals in the air. 



The researchers observed which specific compounds were released during the first few days and how quickly they dropped as time went on.



<h2 class="wp-block-heading" id="h-a-closer-look-at-the-scent">A closer look at the scent</h2>



Monoterpenes emerged as the primary source of the tree’s signature <a href="https://www.earth.com/news/what-gives-pine-trees-fresh-scent/" target="_blank" rel="noreferrer noopener">aroma</a>. These molecules also show up in fragrant products such as certain air fresheners and scented candles. They spiked early in the study, before tapering off within the first 72 hours.



According to the measurements, the initial concentration of monoterpenes equaled levels found in a freshly built house or a newly opened plug-in air freshener. From there, the emissions dropped by nearly tenfold. 



The scientists noted that 52 different types of monoterpenes appeared, illustrating how varied these natural compounds can be.



<h2 class="wp-block-heading" id="h-christmas-trees-and-ozone">Christmas trees and ozone</h2>



The team also introduced ozone to see if it would interact with the tree’s emissions. Ozone near ground level can form through chemical reactions triggered by light. Outdoors, it has been linked to coughing and throat irritation when levels become elevated.



In the chamber, ozone caused monoterpenes to transform into new byproducts. One of these compounds was formaldehyde, measured at about one part per billion in this setup. That number is much smaller compared to the 20 to 30 parts per billion typically found in U.S. houses.



<h2 class="wp-block-heading" id="h-indoor-air-perspectives">Indoor air perspectives</h2>



For some individuals, the rush of VOCs from a freshly displayed tree can lead to mild respiratory responses. The watery eyes or runny nose often show up during the initial phase when emissions peak. Opening a window can help if these symptoms arise.



Outside of that, the changes in indoor air chemistry did not reach levels likely to raise alarms. The data indicated that although there was a clear spike in certain compounds, normal ventilation methods were effective at dispersing them.



<h2 class="wp-block-heading" id="h-simple-steps-to-avoid-issues">Simple steps to avoid issues</h2>



People who prefer a newly cut tree might consider leaving it outside or in a garage for about three days before setting it up indoors. The intensity of monoterpene emissions falls naturally during that waiting period, which can lessen any initial surge.



Keeping doors or windows ajar, especially when first moving the tree into a living area, also allows any <a href="https://www.earth.com/news/common-household-products-expose-people-to-dangerous-chemicals/" target="_blank" rel="noreferrer noopener">lingering chemicals</a> to escape. These small adjustments may help families enjoy a traditional tree without worrying about minor discomforts.



<h2 class="wp-block-heading" id="h-context-for-the-season">Context for the season</h2>



The investigators pursued this research to fill knowledge gaps about how natural decorations might affect <a href="https://www.earth.com/news/bioengineered-super-plant-acts-as-natural-indoor-air-purifier/" target="_blank" rel="noreferrer noopener">indoor air</a>. The study, published in the journal Indoor Environments, highlights the dynamic relationship between conifer emissions and everyday living spaces.



Beyond Douglas fir trees, many items in our homes give off VOCs that shape the air we breathe. Recognizing the major sources can guide practical ways to manage them, whether through better ventilation or careful selection of household products.



<h2 class="wp-block-heading" id="h-awareness-of-indoor-air-quality">Awareness of indoor air quality </h2>



For those concerned about VOCs, the biggest wave of tree-related emissions occurs early on. Poppendieck advises airing out the living area if irritation becomes noticeable. He also notes that storing the tree for a bit in a cooler spot often eases the transition.



"But for most people, this shouldn't be a major concern. I'm still going to have a Christmas tree in my house," said Poppendieck.



For some, the fresh scent of a real tree remains a part of the season. Awareness of indoor air quality tips can keep the experience enjoyable.



The full study was published in the journal <a href="https://www.sciencedirect.com/science/article/pii/S2950362023000024?via%3Dihub" target="_blank" rel="noreferrer noopener">Indoor Environments</a>.



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Christmas trees and VOCs: The source of that fresh, clean holiday smell

Every holiday season, Americans buy nearly 30 million live Christmas...

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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

[sendtonews key="G9bUoxcjr4-2511624-12187" 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.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



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.

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.esa.int/">European Space Agency</a> features Kainji Lake, a reservoir on the Niger River.



In 1968, Kainji Lake was created by the construction of the Kainji Dam. The Niger River, the third longest in Africa, enters the lake in the north.&nbsp;



According to <a href="https://www.earth.com/news/rivers-in-the-american-west-are-a-lifesaving-resource-for-birds/">ESA</a>, the creation of the lake submerged Foge Island and the town of Bussa and permanently flooded other riverine settlements, leaving around 50,000 people displaced.&nbsp;



Large parts of Foge Island are temporarily exposed during low water tides, and the land is often used by migrating fishermen. Kainji Dam is a dam across the Niger River in Niger State of Central Nigeria. 



Wild mammals occur at relatively low densities due to illegal hunting. Lake Kainji has suffered a dramatic decline as a fishery due to the high numbers of artisanal and subsistence fisherfolk using the lake. It has been suggested that a period of closure, together with controlled fishing rights may help improve fish stocks.



Kainji Lake National Park is the oldest of its kind in Nigeria. The park contains three distinct areas: a part of the Kainji Lake, the Borgu Game Reserve to the west of the lake, and the Zugurma Game Reserve to the southeast. The park is home to around 65 mammal species, 350 bird species, and 30 species of reptiles and amphibians. 



Video/ Image Credit: European Space Agency&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.

Kainji Lake in north central Nigeria

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Today’s Video of the Day from <a href="https://www.igb.illinois.edu/">Carl R. Woese Institute for Genomic Biology</a> reveals how scientists can modify common crops like soybean, rice, and wheat to protect them from heat stress.



“We need to double crop production by 2050 to feed a growing global population, and not only are we not on track to do that, but climate change is further complicating things,” said Amanda Cavanagh, a lecturer at the University of Essex. 



The study is part of Realizing Increased Photosynthetic Efficiency (RIPE), an international research project that aims to develop food crops that turn the sun’s energy into food more efficiently.



“Using an engineering approach we designed multiple alternative metabolic pathways to photorespiration. Testing them in the field showed increases in productivity which led Amanda to significantly move the project forward by showing our engineered plants can withstand pretty extreme temperature stress,” said study co-author and RIPE researcher Paul South.&nbsp;



“As the climate changes and temperature stresses increase the pressure on our global food supply, farmers will need every tool available including engineering approaches like the synthetic biology used here to maintain safe and productive harvests.”



The experts tested plants modified to have more efficient photorespiration to see if they were better adapted to warmer temperatures.&nbsp;



The team found that the engineered plants produced 26 percent more biomass than the wild-type plants exposed to the same temperatures, and had 15 percent less yield loss under the higher temperatures.



Video Credit: Amanda Nguyen/University of Illinois



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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.

Designing crops that can beat the heat

[sendtonews key="QGPzYnXEtN-1712599-12187" type="single"] Today’s Video of the Day from Carl...

This party is made up of crew and performers from Buffalo Bill’s Wild West Show – including the chiefs Blue Horse, American Horse, and Red Shirt. And they’re standing on the deck of the SS State of Nebraska, which set sail for England in 1887. There, the Native Americans would entertain Queen Victoria and hordes of Britons during the monarch’s Golden Jubilee celebrations. Photo Credit: Merritt &amp;amp; Wagner

Embarking for England

Naturally, many Apache bitterly opposed the white settlers who took their lands. This group of scouts, though? They actually worked for the U.S. Army. Yep, the ten men photographed here assisted General George Crook. He was hunting the Apache leader Geronimo, who was finally forced to surrender in 1886 – likely the very year this image was created. Photo Credit: <a href="https://www.gettyimages.co.uk/detail/news-photo/apache-scouts-of-general-george-crook-who-helped-to-track-news-photo/629449617?adppopup=true">U</a>niversal History Archive/Universal Images Group via Getty Images