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...

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

This,Man-made,Vehicle,Reached,A,Record,Speed,Of,635,Thousand

NASA’s Parker Solar Probe is set to achieve its most dangerous feat yet tomorrow, December 24, 2024. After a six-year journey of spiraling closer to the star at the heart of our solar system, the spacecraft is expected to come within 3.8 million miles of the Sun’s surface. 



This tiny distance in cosmic terms lets scientists capture a new type of information, revealing secrets about solar winds, extreme heat, and magnetic fields.



<h2 class="wp-block-heading" id="h-solar-probe-on-the-sun-s-doorstep">Solar probe on the Sun's doorstep</h2>



Engineers have spent years carefully adjusting <a href="https://blogs.nasa.gov/parkersolarprobe/" target="_blank" rel="noreferrer noopener">Parker’s flight path</a> using multiple Venus gravity assists. These flybys reshape the spacecraft’s orbit and tighten its looping path around the Sun. “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,” explained <a href="https://science.nasa.gov/people/dr-arik-posner/" target="_blank" rel="noreferrer noopener">Arik Posner</a>, Parker Solar Probe program scientist at NASA Headquarters, describing this mission’s significance.



Ever since the launch in 2018, Parker’s main goal has been to study the Sun’s outer atmosphere, known as the corona. Tomorrow’s approach, often called <a href="https://cneos.jpl.nasa.gov/glossary/perihelion.html" target="_blank" rel="noreferrer noopener">perihelion</a>, marks a new milestone in that quest. The probe moves at speeds around 430,000 miles per hour, faster than any other spacecraft. At such high velocity, it can swing around our star without getting swallowed. Even so, mission managers won’t receive immediate updates once Parker hits its closest point because signals cannot travel through the intense solar environment.



<h2 class="wp-block-heading" id="h-extreme-heat-and-lasting-protection">Extreme heat and lasting protection</h2>



What sets Parker apart is its resilient heat shield. This 4.5-inch-thick carbon-composite barrier enables the spacecraft’s instruments to continue functioning in an environment where temperatures can reach roughly 2,500 degrees Fahrenheit. Despite the harsh surroundings, the precious science instruments remain near room temperature, thanks to expert engineering by Johns Hopkins University Applied Physics Laboratory (<a href="https://parkersolarprobe.jhuapl.edu/" target="_blank" rel="noreferrer noopener">APL</a>).



During every close approach, Parker is pelted by gusts of solar wind and bathed in radiation. Still, it keeps sending back readings about magnetic fields, <a href="https://www.plasmacoalition.org/plasma_writeups/solar_plasmas.pdf" target="_blank" rel="noreferrer noopener">plasma</a> behavior, and energetic <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">particles</a>. The probe’s data illuminates reasons behind the corona’s blazing heat, which can climb into the millions of degrees, significantly hotter than the visible surface of the Sun. Such puzzling behavior has fascinated scientists for decades.



<h2 class="wp-block-heading" id="h-chasing-the-solar-wind-s-origins">Chasing the solar wind’s origins</h2>



Solar wind, a stream of charged particles flowing away from the Sun at speeds topping one million miles per hour, plays a major role in <a href="https://science.nasa.gov/sun/what-is-the-solar-wind/">space weather</a>. 



By skimming through the corona, Parker records fresh evidence of how these particles speed up and scatter across the solar system. The answers may help experts forecast disturbances that affect satellites and astronaut safety. Surges of these charged particles can disable communication systems or even disrupt power grids on Earth.



For researchers, big questions remain. How does the <a href="https://science.nasa.gov/sun/what-is-the-solar-wind/">solar wind</a> pick up its pace so dramatically? Is there a specific region in the corona that triggers bursts of fast-moving particles? 



Parker’s measurements bring us closer to unraveling these mysteries. Officials at NASA say that by tomorrow’s approach, new layers of data will help them see patterns not possible to detect from a greater distance.



<h2 class="wp-block-heading" id="h-solar-probe-and-the-sun-s-active-cycle">Solar probe and the Sun's active cycle</h2>



The Sun moves through an 11-year activity cycle. Right now, it is in an active phase, meaning increased sunspots, <a href="https://www.earth.com/news/secondary-peak-extreme-geomagnetic-solar-storm-expected-today/" target="_blank" rel="noreferrer noopener">solar flares</a>, and <a href="https://www.swpc.noaa.gov/phenomena/coronal-mass-ejections" target="_blank" rel="noreferrer noopener">coronal mass ejections</a>. 



Researchers are tracking not only Parker’s journey but also the Sun’s changing patterns. Sometimes these outbursts interact with Earth’s magnetosphere and spark colorful auroras, even in places unused to such displays. And although most solar weather events are harmless for life on Earth, severe storms can interfere with GPS systems or satellites.



This is why Parker’s findings are so relevant. Gaining a better understanding of how energetic solar events begin could lead to timelier warnings, giving operators on Earth a heads-up to power down sensitive instruments or adjust satellite orbits.



<h2 class="wp-block-heading" id="h-paying-tribute-to-eugene-parker">Paying tribute to Eugene Parker</h2>



In 2017, NASA renamed the probe after <a href="https://news.uchicago.edu/story/eugene-parker-legendary-figure-solar-science-and-namesake-parker-solar-probe-1927-2022">Dr. Eugene N. Parker</a>, the first person to predict the solar wind in the 1950s. He introduced key ideas about how stars interact with their surroundings. The mission’s name honors his influential work. Dr. Parker passed away in 2022, but his legacy continues. 



The data this spacecraft is sending back not only expands knowledge of <a href="https://www.earth.com/news/tracing-solar-wind-directly-to-its-source-for-the-first-time/" target="_blank" rel="noreferrer noopener">solar physics</a> but also shows how correct Dr. Parker’s early theories were.



<h2 class="wp-block-heading" id="h-record-setting-solar-probe-flyby">Record-setting Solar Probe flyby</h2>



Mission operations expect Parker to reach perihelion at 6:53 a.m. EST on December 24. 



At that time, the spacecraft will run autonomously, and engineers at APL will wait until December 27 for a beacon tone confirming a safe passage around the Sun. “No human-made object has ever passed this close to a star, so Parker will truly be returning data from uncharted territory. We’re excited to hear back from the spacecraft when it swings back around the Sun,” 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. 



When that update arrives, scientists will study Parker’s recent measurements to identify potential clues about solar wind origins and coronal heating. Each orbit is another chance to witness the scorching conditions near our star. At the same time, the probe helps refine predictions about solar eruptions that might drive future storms toward Earth.



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



Beyond the scientific breakthroughs, Parker’s success can have practical benefits for technology we rely on every day. Our society depends on GPS signals and stable power systems, and <a href="https://www.earth.com/news/team-creates-video-showing-the-sun-in-gamma-rays-over-a-14-year-period/" target="_blank" rel="noreferrer noopener">major solar events</a> can disrupt both. By learning how to anticipate strong solar winds or flares, experts might one day keep satellites out of harm’s way or shield power grids from unexpected surges.



Tomorrow’s close approach continues a streak of remarkable achievements for NASA. As Parker zips through the corona, it gathers observations that no other mission could obtain. The craft appears ready for another sizzling pass, thanks to the robust thermal design and careful planning. 



Whether it’s helping forecast solar tempers or refining our knowledge of basic astrophysical processes, Parker remains on track to change the way we see the Sun.



Learn more about <a href="https://science.nasa.gov/mission/parker-solar-probe/" target="_blank" rel="noreferrer noopener">NASA's Parker Solar Probe here...</a>



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Spacecraft flew through the Sun's atmosphere today for the first time ever

NASA’s Parker Solar Probe is set to achieve its most...

If all the world's a stage, and all the species merely players, then their exits and entrances can be found in the rock record. This poetic perspective highlights the continuous evolution and unfolding of life’s history, a narrative that is etched into fossils and the layers of sediment in which they are found.



A recent Virginia Tech analysis has now extended this narrative back to nearly 2 billion years ago, offering a more complete picture of life's origin, diversification, and extinction.



<h2 class="wp-block-heading" id="h-expanding-the-chart-of-life">Expanding the chart of life</h2>



Fossil evidence has charted evolutionary milestones over the past half-billion years, but researchers have now pushed this timeline even further back.



The study, led by <a href="https://www.vt.edu" target="_blank" rel="noreferrer noopener">Virginia Tech</a> geobiologist Shuhai Xiao, expands our <a href="https://www.earth.com/news/discovery-evolution-not-random-gene-families-pangenome-influence-called-revolutionary/" target="_blank" rel="noreferrer noopener">understanding of ancient life</a> to the Proterozoic Eon, which spans 2,500 million to 539 million years ago. 



During this era, life forms were typically smaller and softer, such as sea sponges without mineral skeletons, which were less likely to leave fossil traces.



“This is the most comprehensive and up-to-date analysis of this period to date,” said Xiao. "And more importantly, we’ve used a graphic correlation program that allowed us to achieve greater temporal resolution.”



The team’s findings provide a high-resolution analysis of the global diversity and evolution of Proterozoic life. This chart now offers valuable insights into how life’s story played out during this vast period.



<h2 class="wp-block-heading" id="h-understanding-proterozoic-life-the-basics">Understanding proterozoic life -- the basics</h2>



During the <a href="https://www.earth.com/news/rewrite-the-textbooks-life-on-earth-did-not-arise-due-to-increased-oxygen-levels/" target="_blank" rel="noreferrer noopener">Proterozoic eon</a>, which lasted from about 2.5 billion to 541 million years ago, life on Earth was mostly simple and microscopic. Imagine tiny single-celled organisms like bacteria and algae swimming in the oceans. 



These early life forms played a huge role in shaping our planet. For example, they produced oxygen through photosynthesis, which gradually filled the atmosphere and made it possible for more complex life to develop later on. 



Around the middle of the Proterozoic, more advanced cells called <a href="https://www.earth.com/news/earths-oldest-organisms-ever-discovered-show-dazzling-diversity-and-complexity/" target="_blank" rel="noreferrer noopener">eukaryotes</a> appeared. These cells are the building blocks of all plants and animals today, featuring a nucleus and other specialized structures inside them.



As the Proterozoic eon progressed, life started to get a bit more interesting. Towards the end of this time, some of these eukaryotic cells began to form simple multicellular organisms, laying the groundwork for the incredible diversity of life we see today. 



Fossils from this era show the first signs of tiny colonies of cells and simple sea creatures. Even though life was still mostly confined to the oceans, these early innovations set the stage for the explosion of life that would happen in the next eon, the Phanerozoic.



<h2 class="wp-block-heading" id="h-evolution-of-proterozoic-marine-eukaryotes">Evolution of proterozoic marine eukaryotes</h2>



Xiao and his team studied the evolution of ancient marine eukaryotes, which are organisms with cells that have a nucleus. 



These early eukaryotes were the ancestors of animals, <a href="https://www.earth.com/news/ferns-evolving-backward-a-new-look-at-the-evolution-of-life/" target="_blank" rel="noreferrer noopener">plants</a>, and fungi, and thus they paved the way for complex life on Earth.



The researchers found that eukaryotes first appeared at least 1.8 billion years ago. For the next billion years, often called the "boring billion," not much changed.



Species evolved slowly, and diversity remained stable, with few new species emerging or old ones going extinct.



This calm period eventually ended as Earth experienced dramatic changes. Shifts in the environment and evolution then brought a surge in diversity and set the stage for the development of the complex ecosystems we know today.



<h2 class="wp-block-heading" id="h-snowball-earth-s-impact-on-the-evolution-of-life">Snowball Earth's impact on the evolution of life</h2>



Between 720 million and 635 million years ago, the planet experienced at least two severe ice ages, known as Snowball Earth events. These global glaciations plunged Earth into an icy grip, and reshaped <a href="https://www.earth.com/news/how-life-and-environment-co-evolved-over-500-million-years/" target="_blank" rel="noreferrer noopener">life’s trajectory</a>.



“The ice ages were a major factor that reset the evolutionary path in terms of diversity and dynamics,” Xiao explained. “We see rapid turnover of eukaryotic species immediately after glaciation. That’s a major finding.”



When the ice melted, evolutionary activity surged, marking the end of the “boring billion” and ushering in a more dynamic era of biodiversity.



<h2 class="wp-block-heading" id="h-more-questions-than-answers">More questions than answers</h2>



The study on eukaryotic evolution raises important questions about how environmental and evolutionary forces influenced the development of life on Earth. 



For instance, why did eukaryotic evolution remain so slow and stable during the "boring billion," a period marked by low species turnover?



What triggered the rapid evolutionary changes after the <a href="https://www.earth.com/news/snowball-earth-event-set-the-stage-for-complex-life/" target="_blank" rel="noreferrer noopener">Snowball Earth events</a>, when the planet thawed from extreme glaciation?



Key factors under consideration include whether changes in climate and rising atmospheric oxygen levels played a role in accelerating evolution. 



Additionally, scientists wonder whether competition and interactions among organisms created an "evolutionary arms race," that drove species to evolve faster. 



According to Xiao, the team's findings create a foundation for future research. By analyzing the patterns revealed in this study, scientists can delve deeper into the complex relationship between Earth's changing environments and the evolution of life.



<h2 class="wp-block-heading" id="h-new-perspective-on-the-evolution-of-life">New perspective on the evolution of life</h2>



The study of proterozoic life enhances our understanding of how early eukaryotes - the ancestors of modern animals, plants, and fungi - evolved.



The research also reveals how living organisms and Earth’s environment influenced each other in <a href="https://www.earth.com/news/earths-evolution-was-shaped-by-environmental-crises-land-and-sea/" target="_blank" rel="noreferrer noopener">complex and interconnected ways</a> over billions of years.



By extending the timeline of life’s history, this research gives scientists a detailed framework to explore unanswered questions about Earth’s ancient past. It helps us see how events from billions of years ago shaped the planet and life as we know it today.



The study is published in the journal <a href="https://www.science.org/doi/10.1126/science.adm9137" target="_blank" rel="noreferrer noopener">Science</a>.



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Timeline of life’s evolution extended by nearly 1.5 billion years

If all the world's a stage, and all the species...

This,Is,A,3d,Illustration,Of,Cosmic,Microwave,Background,,Electromagnetic

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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Timescape: Dark energy doesn't exist, resulting in 'lumpy' universe expansion

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

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The diverse landscapes of coastal Queensland Today&#8217;s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> explores the diverse landscapes along the coast of North Queensland, Australia.



The video highlights five features that stand out along the coastal region of Queensland, including the Burdekin River and Lake Dalrymple.&nbsp;



The image was captured on May 7, 2021 by the Operational Land Imager (OLI) on Landsat 8.&nbsp;Norman Kuring of NASA’s Ocean Biology group used color-filtering techniques to draw out the fine details in the water, but the features are natural.&nbsp;



Queensland has an extravagantly diverse landscape that is dominated by its extensive coastline, which is home to more than 60 percent of its resident population. The state is famous for tropical islands and white sandy beaches. 



Sound coastal planning and management is vital to help protect and conserve the coast’s important cultural, ecological and natural values. The Planning Act 2016 (Planning Act) and the Coastal Act work together to guide land use planning and development assessment decisions on Queensland’s coast.



Eastern Queensland is dominated by the Great Dividing Range in contrast to the low-relief of western areas. East of the Great Dividing Range is a narrow coastal strip, known as the Australian north-east coast drainage division which contains most of the state&#8217;s population.



Video Credit: NASA Earth Observatory&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