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 

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"

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