<p>Today's Image of the Day from the European Space Agency features the galaxy NGC 2090, located approximately 40 million light-years away in the constellation Columba.</p>



<p>NGC 2090 is a stunning spiral galaxy that is notable for its well-defined structure, featuring a bright central core surrounded by tightly wound spiral arms.&nbsp;</p>



<p>These arms are filled with young, hot stars and interstellar gas, indicating active star formation.&nbsp;</p>



<p>Captured by the Webb Telescope’s MIRI and NIRCam instruments, the image reveals the galaxy's winding spiral arms and the swirling gas and dust of its disc in magnificent and unique detail, noted <a href="https://www.esa.int/ESA_Multimedia/Images" target="_blank" rel="noreferrer noopener">ESA</a>. </p>



<h2 class="wp-block-heading" id="h-observations-of-ngc-2090">Observations of NGC 2090</h2>



<p>The galaxy’s spiral pattern is relatively symmetrical, making it a fascinating object of study for astronomers interested in galactic evolution and dynamics.&nbsp;</p>



<p>Observations of NGC 2090, including those conducted by the <a href="https://www.earth.com/news/hubble-helps-solve-the-mystery-of-a-young-eruptive-star/" target="_blank" rel="noreferrer noopener">Hubble</a> Space Telescope, have provided valuable insights into the properties of its stellar populations, gas content, and the nature of its spiral structure.</p>



<p>“NGC 2090 was one of many galaxies studied by the NASA/ESA Hubble Space Telescope to refine the measurement of the Universe’s expansion rate, or ‘Hubble constant,’” said ESA.&nbsp;</p>



<p>“This can be done by observing a special type of variable stars named ‘Cepheids’ in relatively nearby galaxies.”</p>



<h2 class="wp-block-heading" id="h-new-insights-into-ngc-2090">New insights into NGC 2090</h2>



<p>A Cepheid-based measurement from 1998 indicated that NGC 2090 is 37 million light-years away from Earth. However, the latest measurements suggest that the galaxy is 40 million light-years away.</p>



<p>“Already before that Hubble project in 1998, NGC 2090 had been well studied as a very prominent nearby example of star formation,” noted ESA.&nbsp;</p>



<p>“Described as a ‘flocculent’ spiral, this galaxy has a patchy, dusty disc and arms that are flaky or not visible at all. We can see those patterns well in Hubble's visible-light images. However, Webb’s NIRCam near-infrared data reveal the spiral arms with remarkable clarity.”&nbsp;</p>



<h2 class="wp-block-heading" id="h-what-are-spiral-galaxies">What are spiral galaxies?</h2>



<p><a href="https://www.earth.com/news/the-mesmerizing-beauty-of-spiral-galaxies/" target="_blank" rel="noreferrer noopener">Spiral galaxies</a> are among the most common and visually striking types of galaxies in the universe.&nbsp;</p>



<p>They are characterized by their flat, disk-like shape with a bright central bulge surrounded by sweeping spiral arms.&nbsp;</p>



<h3 class="wp-block-heading" id="h-spiral-arms-and-central-bulge-nbsp">Spiral arms and central bulge&nbsp;</h3>



<p>The arms of a spiral galaxy are regions where stars, gas, and dust are concentrated, often glowing brightly with the light of young, hot stars that form within them.&nbsp;</p>



<p>The central bulge typically contains older stars and can host a supermassive black hole at its core.&nbsp;</p>



<h3 class="wp-block-heading" id="h-types-of-spiral-galaxies-nbsp">Types of spiral galaxies&nbsp;</h3>



<p>Spiral galaxies are classified into different types based on how tightly their arms are wound and the size of their central bulge, ranging from tightly wound "Sa" galaxies to loosely wound "Sc" types.</p>



<h3 class="wp-block-heading" id="h-star-formation-nbsp">Star formation&nbsp;</h3>



<p>The structure of spiral galaxies is maintained by the interplay of gravity and angular momentum, with a rotating disk of stars and gas giving rise to their iconic shape.&nbsp;</p>



<p>They are active sites of <a href="https://www.earth.com/news/massive-star-redefines-our-understanding-of-stellar-evolution/" target="_blank" rel="noreferrer noopener">star formation</a> due to the abundance of gas in their arms.&nbsp;</p>



<p>Spiral galaxies often have a halo of older stars and globular clusters surrounding their disks, which provides clues about their formation and evolution.&nbsp;</p>



<h3 class="wp-block-heading" id="h-barred-spiral-galaxy">Barred spiral galaxy</h3>



<p>The <a href="https://www.earth.com/news/milky-way-galaxy-is-surrounded-by-massive-magnetic-fields/" target="_blank" rel="noreferrer noopener">Milky Way</a>, the galaxy that contains our Solar System, is a prime example of a barred spiral galaxy, a subtype where a bar-shaped structure of stars extends from the central bulge.&nbsp;</p>



<h2 class="wp-block-heading" id="h-the-constellation-columba-nbsp">The constellation Columba&nbsp;</h2>



<p>Columba is a small and relatively faint constellation in the southern sky, whose name means "dove" in Latin. It was introduced in the late 16th century by the Dutch astronomer Petrus Plancius and first appeared in a celestial atlas by Johann Bayer in 1603.&nbsp;</p>



<p>The <a href="https://www.earth.com/news/super-jupiter-discovered-in-the-great-bear-constellation/" target="_blank" rel="noreferrer noopener">constellation</a> is said to represent the dove sent out by Noah during the biblical flood, tying it to themes of hope and peace.</p>



<p>Columba lies near the larger constellation Canis Major and is bordered by others such as Lepus and Puppis.&nbsp;</p>



<p>Although it lacks particularly bright stars, its most notable star, Alpha Columbae (also called Phact), shines at a magnitude of approximately 2.6 and is a hot blue-white star. Beta Columbae, another prominent star in the constellation, is a slightly cooler, yellow-white star.</p>



<p>The constellation is best viewed from the Southern Hemisphere during the summer months, though it can also be seen from lower latitudes in the Northern Hemisphere.&nbsp;</p>



<p>Image Credit: NASA/ESA/CSA James Webb Space Telescope&nbsp;</p>



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Webb unveils spiral galaxy NGC 2090 in magnificent detail

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

<p>Today's <strong>Image of the Day</strong> from the European Space Agency features the galaxy I Zwicky 18, which was captured in remarkable detail by the James Webb Space Telescope.</p>



<p>I Zwicky 18 is a blue compact dwarf <a href="https://www.earth.com/news/newly-discovered-stars-milky-way-are-old-as-universe/" target="_blank" rel="noreferrer noopener">galaxy</a> located approximately 59 million light-years away in the constellation Ursa Major.&nbsp;</p>



<h2 class="wp-block-heading" id="h-star-formation-in-i-zwicky-18">Star formation in I Zwicky 18</h2>



<p>The galaxy is notable for its relatively young appearance and the fact that it contains very few heavy elements. These characteristics indicate that it has experienced little <a href="https://www.earth.com/news/baby-stars-release-sneezes-of-gas-and-dust-as-they-develop/" target="_blank" rel="noreferrer noopener">star formation</a> compared to other galaxies of similar age.</p>



<p>“The galaxy was first identified by Swiss astronomer Fritz Zwicky in the 1930’s and resides roughly 59 million light-years from Earth,” noted <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>. “This galaxy has gone through several sudden bursts of star formation.”&nbsp;</p>



<p>According to ESA, I Zwicky 18 is typical of the kinds of galaxies that inhabited the early universe and is much smaller than our <a href="https://www.earth.com/news/runaway-star-j1249-36-spotted-trying-to-escape-our-milky-way-galaxy/" target="_blank" rel="noreferrer noopener">Milky Way</a>.</p>



<h2 class="wp-block-heading" id="h-webb-telescope-image-of-the-galaxy">Webb telescope image of the galaxy</h2>



<p>“Two major starburst regions are embedded in the heart of the galaxy. The wispy brown filaments surrounding the central starburst region are bubbles of gas that have been heated by stellar winds and intense ultraviolet radiation unleashed by hot, young stars,” noted ESA.</p>



<p>“A companion galaxy resides nearby to the dwarf galaxy, which can be seen at the bottom of the wider-field image. The companion may be interacting with the dwarf galaxy and may have triggered that galaxy's recent star formation.”&nbsp;</p>



<p>ESA explained that the “orange blobs” surrounding the galaxy are the dim glow from ancient fully formed galaxies at much larger distances.</p>



<h2 class="wp-block-heading" id="h-key-characteristics-of-i-zwicky-18">Key characteristics of I Zwicky 18</h2>



<p>As previously mentioned, the galaxy has a very low abundance of elements heavier than hydrogen and helium, suggesting that it has not undergone significant stellar processing.</p>



<h3 class="wp-block-heading" id="h-young-stellar-population-nbsp">Young stellar population&nbsp;</h3>



<p>Despite its old age, I Zwicky 18 contains many young, hot stars. This suggests that it might have experienced a burst of <a href="https://www.earth.com/news/hubble-detects-awe-inspiring-newborn-star/" target="_blank" rel="noreferrer noopener">star formation</a> relatively recently in its history.</p>



<h3 class="wp-block-heading" id="h-interstellar-medium-nbsp">Interstellar medium&nbsp;</h3>



<p>The galaxy has a high density of gas, which is a prime ingredient for star formation. This gas is mostly in the form of hydrogen.</p>



<h3 class="wp-block-heading" id="h-unusual-characteristics">Unusual characteristics</h3>



<p>Its characteristics are more typical of primordial galaxies found in the early universe, making it a valuable object of study for understanding galaxy formation and evolution.</p>



<p>Ultimately, I Zwicky 18 provides insights into the conditions and processes that might have been prevalent in the early universe.</p>



<h3 class="wp-block-heading" id="h-life-cycles-of-stars-and-dust">Life cycles of stars and dust</h3>



<p>The image was captured as part of a Webb program to study the life cycle of dust in I Zw 18.&nbsp;</p>



<p>“Scientists are now building off of previous research with Hubble obtained at optical wavelengths, studying individual dusty stars in detail with Webb’s equivalent spatial resolution and sensitivity at infrared wavelengths.”&nbsp;</p>



<p>ESA noted that this galaxy is of particular interest as its content of elements heavier than helium is one of the lowest of all known <a href="https://www.earth.com/news/early-galaxy-formation-occurred-much-faster-than-we-thought/" target="_blank" rel="noreferrer noopener">galaxies</a> in the local universe.&nbsp;</p>



<p>“Such conditions are thought to be similar to those in some of the first star-forming galaxies at high redshift, so the Webb study of I Zw 18 should shed light on the life-cycle of stars and dust in the early universe.”</p>



<h2 class="wp-block-heading" id="h-the-constellation-ursa-major">The constellation Ursa Major </h2>



<p>Ursa Major, also known as the Great Bear, is one of the most prominent and easily recognizable constellations in the northern sky. </p>



<p>Its name, "Ursa Major," means "Great Bear" in Latin, and it has been a significant part of various mythologies and star lore across cultures for thousands of years. </p>



<p>One of the most famous asterisms within Ursa Major is the Big Dipper, a group of seven bright stars that form a shape resembling a ladle or dipper. The Big Dipper is often used as a navigation tool because it points to Polaris, the North Star, located in the nearby constellation Ursa Minor.</p>



<p>Ursa Major is best viewed in the northern hemisphere and is circumpolar, meaning it is visible year-round for much of the Northern Hemisphere. Its position changes with the seasons, rotating around Polaris, the North Star.</p>



<p>Image Credit: NASA/ESA/CSA James Webb Space Telescope</p>



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Dwarf galaxy provides a window into the early universe

<p>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.</p>



<p>“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>.</p>



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



<p>“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;</p>



<p>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.</p>



<p>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.”</p>



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



<p>“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.</p>



<p>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.</p>



<p>“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.</p>



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



<p>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>. </p>



<p>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.</p>



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



<p>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;</p>



<p>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.</p>



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



<p>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;</p>



<p>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.</p>



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



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



<p>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>.</p>



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



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



<p>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.</p>



<p>The retreat of glaciers is considered one of the clearest indicators of climate change. Some glaciers are retreating at unprecedented rates, indicating accelerating climate impacts.</p>



<p>Image Credit: NASA Earth Observatory</p>



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Retreating glaciers and expanding meltwater lakes in Alaska

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

<p>Today's <strong>Image of the Day</strong> from the European Space Agency features the star-forming region NGC 604, which is located 2.73 million light-years away from Earth in the Triangulum Galaxy (M33). The image was captured by the James Webb Space Telescope.</p>



<p>By studying regions like NGC 604, astronomers can gain insights into the complex interactions between stars and the interstellar medium, as well as the conditions that lead to the birth of stars. This, in turn, helps in understanding the evolution of <a href="https://www.earth.com/news/galaxies-like-our-own-milky-way-are-not-unique/" target="_blank" rel="noreferrer noopener">galaxies</a> and the universe as a whole.</p>



<h2 class="wp-block-heading" id="h-massive-stars-of-ngc-604">Massive stars of NGC 604</h2>



<p>"Sheltered among NGC 604’s dusty envelopes of gas are more than 200 of the hottest, most massive kinds of stars, all in the early stages of their lives," said <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>.</p>



<p>"These types of stars are known as B-types and O-types, the latter of which can be more than 100 times the mass of our own Sun. It’s quite rare to find this concentration of them in the nearby universe. In fact, there’s no similar region within our own Milky Way galaxy."</p>



<p>According to ESA, this concentration of massive stars, combined with its relatively close distance, means NGC 604 gives astronomers an opportunity to study these objects at a fascinating time early in their life.</p>



<h2 class="wp-block-heading" id="h-gigantic-region-of-ionized-hydrogen">Gigantic region of ionized hydrogen</h2>



<p>NGC 604 is one of the largest known regions of ionized hydrogen, also known as an H II region. This nebula is significantly larger than the Orion Nebula, which is one of the most well-known H II regions in our own <a href="https://www.earth.com/news/large-amount-of-dark-matter-may-be-missing-from-the-milky-way/" target="_blank" rel="noreferrer noopener">Milky Way galaxy</a>.&nbsp;</p>



<p>NGC 604 spans about 1,500 light-years across, making it one of the largest H II regions in the Local Group of galaxies. This group includes the Milky Way, the Andromeda Galaxy, and about 54 other smaller galaxies. </p>



<h2 class="wp-block-heading" id="h-ngc-604-starburst-phenomenon">NGC 604 starburst phenomenon </h2>



<p>Within NGC 604, there are hundreds of young, hot, massive <a href="https://www.earth.com/news/stars-at-the-edge-of-our-milky-way-galaxy-travel-more-slowly/" target="_blank" rel="noreferrer noopener">stars</a>. These stars have ionized the surrounding gas, causing it to glow and creating the nebula. The region is a prime example of a starburst phenomenon, where stars form at a much higher rate than in typical galactic conditions.</p>



<p>“The bright orange streaks in this image signify the presence of carbon-based molecules known as polycyclic aromatic hydrocarbons, or PAHs," explained ESA.</p>



<p>"As you travel further from the immediate cavities of dust where the star is forming, the deeper red signifies molecular hydrogen. This cooler gas is a prime environment for star formation. Ionized hydrogen from ultraviolet radiation appears as a white and blue ghostly glow."</p>



<h2 class="wp-block-heading" id="h-more-about-star-formation">More about star formation </h2>



<p>Star formation is crucial for the evolution of galaxies and the synthesis of heavy elements. In the cores of stars, elements heavier than helium are created.</p>



<p>The elements are spread throughout the <a href="https://www.earth.com/news/ancient-stars-shakti-shiva-shaped-milky-way-galaxy/" target="_blank" rel="noreferrer noopener">galaxy</a> when stars reach the end of their lives and expel their material - either gently through winds or violently via supernova explosions. This enriching process allows for the formation of new stars and planets, and ultimately, the potential for life.</p>



<h3 class="wp-block-heading">Cloud collapse</h3>



<p>The process begins when part of a molecular cloud becomes unstable and starts to collapse under its own gravity. This can be triggered by events like shock waves from nearby <a href="https://www.earth.com/news/supernova-explosions-could-damage-distant-planets/" target="_blank" rel="noreferrer noopener">supernovae</a>, galactic collisions, or the influence of other massive stars.</p>



<h3 class="wp-block-heading">Formation of a protostar</h3>



<p>As the cloud collapses, it fragments into smaller clumps. Each clump will eventually form one or more stars. </p>



<p>The material within these clumps continues to fall inward, heating up as it does so, eventually forming a warm core called a protostar. At this stage, the protostar is not yet hot enough for nuclear fusion (the process that powers stars) to occur.</p>



<h3 class="wp-block-heading">Accretion disk</h3>



<p>Around the protostar, material from the surrounding cloud continues to fall inward, forming a rotating disk. This material slowly accretes onto the protostar, increasing its mass.</p>



<h3 class="wp-block-heading">Nuclear fusion begins</h3>



<p>Once the core of the protostar reaches a high enough temperature and pressure, hydrogen atoms begin to fuse into helium, releasing energy in the process. This marks the transition from a protostar to a main sequence star, like our sun.</p>



<h3 class="wp-block-heading">Main sequence and beyond</h3>



<p>The star will spend the majority of its life in the main sequence stage, where it balances the gravitational forces trying to collapse it and the outward pressure from nuclear fusion. </p>



<p>Eventually, the star will exhaust its hydrogen fuel. Its subsequent evolution will depend on its initial mass, leading to various end stages such as red giants, supernovae, neutron stars, or black holes.</p>



<p>Image Credit: NASA/ESA/CSA James Webb Space Telescope</p>



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Young, massive stars in the Triangulum Galaxy

<p>Today's Image of the Day from NASA Earth Observatory features the Messak Settafet, a rocky plateau located in the central Sahara Desert. It is part of the greater Messak Plateau, which stretches between the Erg Uan Kasa and the Murzuq Sand Sea.&nbsp;</p>



<p>The plateau's surface is characterized by blackened sandstone, sculpted by thousands of years of wind erosion. This dark patina, often referred to as "desert varnish," adds to its distinctive appearance. The region is starkly beautiful but harsh, with extreme temperatures and minimal <a href="https://www.earth.com/news/even-desert-plants-are-not-immune-to-climate-stress/" target="_blank" rel="noreferrer noopener">vegetation</a>.</p>



<h2 class="wp-block-heading" id="h-image-of-the-messak-settafet">Image of the Messak Settafet</h2>



<p>“Towering over the desert in southwestern Libya, the Messak Settafet plateau resembles the wall of a giant fortress, with its dark, erosion-resistant sandstone separating the Ubari Sand Sea to the north and the Marzūq Sand Sea to the south,” noted NASA.</p>



<p>“The large outcrop of Cretaceous rock features a sharp escarpment on its north side. The cliff, some 300 meters (1,000 feet) high in places, is lined with a thin dark shadow.”&nbsp;</p>



<p>“Dark debris from rockfalls is visible to the north. Note that an optical illusion called relief inversion can make high-elevation areas appear low and vice versa when shadows appear on the northern side of a feature.”</p>



<p>Archaeological significance of the plateau&nbsp;</p>



<p>Messak Settafet is often referred to as the "land of stone tools" because it is one of the world's largest sites for prehistoric tools.&nbsp;</p>



<p>The area is littered with countless <a href="https://search.app?link=https%3A%2F%2Fwww.earth.com%2Fnews%2Fstone-tool-discovery-challenges-entire-theory-of-human-evolution%2F&amp;utm_campaign=aga&amp;utm_source=agsadl2%2Csh%2Fx%2Fgs%2Fm2%2F4" target="_blank" rel="noreferrer noopener">stone tools</a> and artifacts dating back to various prehistoric periods, including the Acheulean and Neolithic. These tools offer insights into early human technology and adaptation to desert environments.</p>



<p>“Signs of ancient tool making cover much of the plateau’s surface,” said <a href="https://www.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA</a>. “According to one archaeological survey, people discarded so many stone tools and rock fragments on the plateau over hundreds of thousands of years that roughly 75 artifacts per square meter now carpet the surface.” </p>



<p>“That makes this one of the earliest known examples of hominins modifying an entire landscape, according to the University of Cambridge archaeologists who conducted the survey.”</p>



<p>“Other signs of ancient activity include the bright spots that dot the image. These areas were likely quarrying pits where people dug up rocks and crafted them into tools, the archaeologists reported.”&nbsp;</p>



<h2 class="wp-block-heading" id="h-rock-art-on-the-plateau-nbsp">Rock art on the plateau&nbsp;</h2>



<p>The plateau is home to numerous petroglyphs and <a href="https://www.earth.com/news/negev-petroglyphs-ancient-art-rock-carvings-face-erosion-fungi-lichens/" target="_blank" rel="noreferrer noopener">carvings</a>. These engravings depict animals, humans, and symbolic designs, providing valuable clues about the lives, beliefs, and environments of the region's ancient inhabitants. </p>



<p>“For instance, Wadi Mathendous, a prehistoric archaeological site located in the southern part of the plateau, contains engravings of rhinoceroses, crocodiles, hippopotamuses, fighting cats, giraffes, long-horned buffaloes, and elephants. The art is thought to be about 8,000 years old,” said NASA.</p>



<p>Some of the animals depicted, such as giraffes and elephants, indicate that the Sahara was once a <a href="https://search.app?link=https%3A%2F%2Fwww.earth.com%2Fnews%2Fa-lush-green-sahara-desert-helped-early-humans-migrate-out-of-africa%2F&amp;utm_campaign=aga&amp;utm_source=agsadl2%2Csh%2Fx%2Fgs%2Fm2%2F4" target="_blank" rel="noreferrer noopener">much wetter</a> and more hospitable environment.</p>



<p>Cultural significance of the Messak Settafet</p>



<p>Messak Settafet forms part of the Rock-Art Sites of Tadrart Acacus, a UNESCO World Heritage Site since 1985. This designation highlights the area's importance for understanding early human culture and environmental changes in the Sahara.</p>



<p>The plateau has been a critical area for studying the migration and adaptation of early humans. Its archaeological richness offers a glimpse into how humans thrived in this region during periods when the climate was wetter.</p>



<p>“Although the plateau now receives less than 0.4 inches of rain annually, clues in the landscape make clear it was once much wetter,” noted NASA.</p>



<p>“Deeply incised dried stream valleys, or wadis, crisscross the plateau, indicating significant past water flow. The small, bright features scattered across the plateau are sand and silt deposits left where water once pooled.”</p>



<p>The Messak Settafet, like many remote <a href="https://www.earth.com/news/sahara-desert-dust-storms-carry-harmful-bacteria-and-fungi-around-the-globe/" target="_blank" rel="noreferrer noopener">desert</a> regions, faces challenges such as erosion, vandalism of ancient rock art, and the potential impacts of development. Efforts to preserve its archaeological treasures are vital for protecting its cultural and scientific significance.</p>



<p>The image was captured November 17, 2024 by the Operational Land Imager-2 (OLI-2) on Landsat 9 on&nbsp;</p>



<p>Image Credit: NASA Earth Observatory</p>



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Messak Settafet plateau in the Sahara Desert

<p>The rise in carbon dioxide (CO2) levels in our world's atmosphere is fueling an environmental threat to marine life. Ocean acidification is growing in magnitude as it moves into deeper waters.</p>



<p>Jens Müller and Nicolas Grube are environmental physicists in the Institute of Biogeochemistry and Pollutant Dynamics at ETH Zurich. They set out to investigate the consequences of acidification by developing a 3D model of our oceans.</p>



<p>The research, recently published in the journal <em>Science Advances</em>, sheds light on how ocean acidification has intensified since the industrial revolution kicked off.</p>



<h2 class="wp-block-heading" id="h-connecting-carbon-and-ocean-acidification">Connecting carbon and ocean acidification</h2>



<p>Science has shown us that carbon emissions heat up Earth's atmosphere and oceans. But there's more.</p>



<p>When dissolved in seawater, CO2 causes chemical reactions that drop the pH levels, making it acidic. This is similar to what happens when your beverage gets that fizzy zing from carbon dioxide. </p>



<p>The process may sound simple, but it poses a serious threat to marine life. Our oceans are home to many sea creatures whose survival depends on the chemical stability of the ocean.</p>



<p>Coral reefs are especially at risk. The acidic waters hinder their skeleton-building ability, resulting in coral bleaching and eventually death. This creates a domino effect on marine ecosystems, affecting countless marine species.</p>



<h2 class="wp-block-heading" id="h-mapping-ocean-acidification-depths">Mapping ocean acidification depths</h2>



<p>Müller and Grube carefully designed an experiment to untangle the spread of ocean acidification. </p>



<p>Their focus: How deep down has acidification seeped into our oceans over time? To answer this, they developed an ocean model simulating the effects of rising <a href="https://www.earth.com/news/collapse-of-main-atlantic-ocean-circulaton-current-amoc-is-already-happening/" target="_blank" rel="noreferrer noopener">atmospheric CO2 levels</a>.</p>



<p>The model was based on historical data spanning over two centuries, with CO2 estimates for the years 1800, 1994, 2004, and 2014. This gave the researchers a timeline to monitor how acidification spread through the ocean layers.</p>



<h2 class="wp-block-heading" id="h-constructing-the-ocean-model">Constructing the ocean model</h2>



<p>Creating a model of this scale required careful planning. Starting with a standard <a href="https://www.earth.com/news/oceans-cool-the-climate-more-than-previously-realized/" target="_blank" rel="noreferrer noopener">ocean</a> model that simulates water movement and chemistry, the researchers then added data points on CO2 levels and acidification indicators like proton concentrations, pH levels, and aragonite saturation states.</p>



<p>This comprehensive approach enabled the experts to accurately map acidification trends.</p>



<h2 class="wp-block-heading" id="h-acidification-reaches-new-ocean-depths">Acidification reaches new ocean depths</h2>



<p>Ocean acidification is moving deeper into the ocean, with the average depth impacted by acidification measuring around 1,000 meters by 2014.</p>



<p>In regions influenced by the Atlantic meridional overturning current, acidification reached depths of up to 1,500 meters.</p>



<p>But this spread isn't uniform; different ocean regions face varying levels of change due to factors like water circulation patterns and temperature.</p>



<h2 class="wp-block-heading" id="h-marine-life-at-risk">Marine life at risk</h2>



<p>Deeper acidification harms more marine organisms. Tiny creatures like Pteropods, called "sea butterflies," are among the most vulnerable. Their calcium-based shells are highly susceptible to acidic conditions.</p>



<p>A decline in pteropods would disrupt marine ecosystems. Other species, including corals and certain types of plankton, face similar risks.</p>



<h2 class="wp-block-heading" id="h-future-implications-of-deeper-acidification">Future implications of deeper acidification </h2>



<p>Müller and Grube's findings emphasize the urgent need to address carbon emissions. As CO2 levels rise, ocean acidification will only get worse. </p>



<p>The deeper it goes, the harder it is to reverse the impacts. The long-term consequences for marine biodiversity and human communities relying on <a href="https://www.earth.com/news/oceans-hidden-skin-could-protect-us-from-climate-change/" target="_blank" rel="noreferrer noopener">ocean</a> resources are unclear.</p>



<p>Reducing carbon emissions will help slow acidification. Initiatives to shift to renewable energy, enhance energy efficiency, and promote conservation could also contribute.</p>



<p>In addition to mitigation efforts, further research is needed to understand acidification's full impact and to find ways to protect marine life.</p>



<h2 class="wp-block-heading" id="h-addressing-the-challenge-of-ocean-acidification">Addressing the challenge of ocean acidification</h2>



<p>The study by the <a href="https://ethz.ch/en.html" target="_blank" rel="noreferrer noopener">ETH Zurich</a> researchers paints a vivid picture of the hidden changes happening beneath the ocean's surface and the intricate connections between human activities and ocean health.</p>



<p>The new model provides valuable data for those working to tackle this urgent issue.</p>



<p>Addressing the challenge of ocean acidification requires a deeper understanding of its effects and collaborative efforts to reduce carbon emissions. </p>



<p>Innovative research, like modeling acidification trends, offers valuable insights to guide solutions. Protecting our oceans is essential for preserving biodiversity and ensuring a sustainable future for generations to come.</p>



<p>The study is published in the journal <em><a href="https://www.science.org/doi/10.1126/sciadv.ado3103" target="_blank" rel="noreferrer noopener">Science Advances</a>.</em></p>



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Ocean acidification is spreading into deeper waters

The rise in carbon dioxide (CO2) levels in our world's...

<p>Once upon a time, more than a million years ago, the hot savannah near what we now know as Lake Turkana in Kenya served as a bustling hub, where two completely distinct species of hominins left their footprints in history.</p>



<p>Recent discoveries reveal that these two species, engrossed in their search for sustenance, might have unknowingly crossed paths and left a tangible mark on our understanding of human evolution.</p>



<h2 class="wp-block-heading" id="h-mystery-of-hominin-footprints">Mystery of hominin footprints</h2>



<p>Hominin is the term used to group species that branched off the evolutionary tree after the <a href="https://www.earth.com/news/early-humans-preferred-the-mountains-and-it-changed-our-evolution/" target="_blank" rel="noreferrer noopener">ancestors</a> of the great apes diverged, about 6-7 million years ago. </p>



<p>The Hominins thus include all the species that were directly ancestral to humans or were closely related to them.</p>



<p>The fascinating discovery of 1.5-million-year-old footprints is like peering through a window into our past.</p>



<p>According to scientists, this is the first discovery of fossilized tracks where two different species of hominin left their footprints concurrently on the same ancient lake shore.</p>



<p>This finding could help us to understand how hominin species interacted with and affected each other.</p>



<h2 class="wp-block-heading" id="h-a-breakthrough-discovery">A breakthrough discovery</h2>



<p>A recent publication in the journal <em>Science</em> presents irrefutable evidence of different hominin species co-existing in the same space and temporal frame.</p>



<p>The footprints imprinted by individuals of the species <em>Homo erectus</em> and <em>Paranthropus boisei</em>, which are two of the most common hominin species of the Pleistocene Epoch, narrate the story of their lives.</p>



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2024/12/footprints_human-ancestors_Paranthropus-boisei_credit-Chatham-University_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2024/12/footprints_human-ancestors_Paranthropus-boisei_credit-Chatham-University_1s.webp" alt="A footprint hypothesized to have been created by a Paranthropus boisei individual. Credit: Kevin Hatala/Chatham University" class="wp-image-1952149"/></a><figcaption class="wp-element-caption"><em>A footprint hypothesized to have been created by a Paranthropus boisei individual. Credit: Kevin Hatala/Chatham University</em></figcaption></figure>



<p>“Their presence on the same surface, made closely together in time, places the two <a href="https://www.earth.com/news/early-humans-impacted-earth-than-previously-thought-2/" target="_blank" rel="noreferrer noopener">species</a> at the lake margin, using the same habitat,” said Craig Feibel, an author of the study and a professor in the Department of Earth and Planetary Sciences and Department of Anthropology in the <a href="https://sas.rutgers.edu/" target="_blank" rel="noreferrer noopener">Rutgers School of Arts and Sciences</a>.</p>



<h2 class="wp-block-heading" id="h-tracking-hominin-footprints">Tracking hominin footprints</h2>



<p>Feibel, along with researchers led by Cyprian Nyete, discovered the footprints in 2021. A surprise awaited them as they unearthed not just giant bird tracks but hominin footprints as well. </p>



<p>The footprints told an intriguing story. If the two species of hominins didn’t cross paths, they tread the shore within hours of each other, according to Feibel.</p>



<p>“Fossil footprints are exciting because they provide vivid snapshots that bring our fossil relatives to life,” said Kevin Hatala, the study’s first author and an associate professor of biology at <a href="https://www.chatham.edu/" target="_blank" rel="noreferrer noopener">Chatham University</a> in Pittsburgh.</p>



<p>“With these kinds of data, we can see how living individuals, millions of years ago, were moving around their environments and potentially interacting with each other, or even with other animals. That's something that we can't really get from bones or stone tools,” he added.</p>



<h2 class="wp-block-heading" id="h-co-existence-of-two-hominin-species">Co-existence of two hominin species</h2>



<p>The discovery of hominin footprints is, as Feibel puts it, "a bit of serendipity." The findings demonstrate the co-existence of these species and supports a hypothesis that has been around for a while.</p>



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2024/12/footprints_human-ancestors_Homo-erectus_credit-Chatham-University_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2024/12/footprints_human-ancestors_Homo-erectus_credit-Chatham-University_1s.webp" alt="A footprint hypothesized to have been created by a Homo erectus individual. Credit: Kevin Hatala/Chatham University" class="wp-image-1952147"/></a><figcaption class="wp-element-caption"><em>A footprint hypothesized to have been created by a Homo erectus individual. Credit: Kevin Hatala/Chatham University</em></figcaption></figure>



<p>According to fossil records, <em>Homo erectus</em>, our direct <a href="https://www.earth.com/news/humans-first-arrived-in-europe-1-3-million-years-ago/" target="_blank" rel="noreferrer noopener">ancestor</a>, persisted for a million years more than <em>Paranthropus boisei</em>. The reasons behind the extinction of <em>Paranthropus boisei</em> remain unknown.</p>



<h2 class="wp-block-heading" id="h-transcending-the-physical-evidence">Transcending the physical evidence</h2>



<p>The footprints acquire a significant position in the study of human evolution. In Feibel's words, they fall into the category of "trace fossils," that provide non-physical evidence of behavior.</p>



<p>Unlike body fossils (such as bones and teeth) that can be moved by natural forces, trace fossils remain untouched, preserving an authentic record of past behaviors.</p>



<p>The discovery of these footprints opens a gateway into the past by showing directly that distinct kinds of human relatives co-inhabited the same place at the same time. </p>



<p>Even more intriguing is the possibility that the two groups might have interacted, influencing each other in ways we are yet to fully comprehend.</p>



<h2 class="wp-block-heading" id="h-insights-from-ancient-hominin-footprints">Insights from ancient hominin footprints</h2>



<p>The study of these ancient footprints offers valuable insights into the behavior and movement patterns of our prehistoric ancestors. </p>



<p>By examining the size, shape, and stride length of the footprints, researchers can gather information about the individuals' walking speed, body proportions, and possibly even their social dynamics.</p>



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2024/12/footprints_human-ancestors_cross-paths_Paranthropus-boisei_Homo-erectus_credit-Chatham-University_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2024/12/footprints_human-ancestors_cross-paths_Paranthropus-boisei_Homo-erectus_credit-Chatham-University_1s.webp" alt="A 3D computerized model of the surface of the area near Lake Turkana in Kenya shows fossil footprints of Paranthropus boisei (vertical footprints) with separate footprints of Homo erectus forming a perpendicular path. Credit: Kevin Hatala/Chatham University" class="wp-image-1952145"/></a><figcaption class="wp-element-caption"><em>A 3D computerized model of the surface of the area near Lake Turkana in Kenya shows fossil footprints of Paranthropus boisei (vertical footprints) with separate footprints of Homo erectus forming a perpendicular path. Credit: Kevin Hatala/Chatham University</em></figcaption></figure>



<p>This invaluable evidence provides a window into the daily lives and interactions of <em>Homo erectus</em> and <em>Paranthropus boisei</em>, shedding light on our shared history and the complexities of our evolutionary journey.</p>



<h2 class="wp-block-heading" id="h-understanding-human-evolution">Understanding human evolution</h2>



<p>The coexistence and potential interaction between <em>Homo erectus</em> and <em>Paranthropus boisei </em>have significant implications for our understanding of human evolution.</p>



<p>It challenges the linear narrative of human evolution and highlights the complexity and diversity of our <a href="https://www.earth.com/news/humans-arrived-in-south-america-much-earlier-than-we-thought/" target="_blank" rel="noreferrer noopener">evolutionary past</a>. </p>



<p>The presence of multiple species in the same environment suggests that different hominin groups may have occupied distinct ecological niches and developed unique adaptations. </p>



<p>By studying these ancient footprints, we not only unravel the story of our ancestors but also gain a deeper appreciation for the intricate tapestry of human evolution.</p>



<h2 class="wp-block-heading" id="h-the-journey-of-our-prehistoric-ancestors">The journey of our prehistoric ancestors</h2>



<p>The footprints of <em>Homo erectus</em> and <em>Paranthropus boisei</em> provide a tangible narrative of our prehistoric ancestors. They reveal how distinct paths paved the way for our evolution.</p>



<p>“This proves beyond any question that not only one, but two different hominins were walking on the same surface, literally within hours of each other,” Feibel said. </p>



<p>“The idea that they lived contemporaneously may not be a surprise. But this is the first time demonstrating it. I think that's really huge.”</p>



<p>The study is published in the journal <a href="https://www.science.org/doi/10.1126/science.ado5275" target="_blank" rel="noreferrer noopener"><em>Science</em></a>.</p>



<p>Image Credit: Kevin Hatala/Chatham University</p>



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Two species of human ancestors literally crossed paths 1.5 million years ago

Once upon a time, more than a million years ago,...

<p>The great evolutionary leap from unicellular organisms to the animal kingdom took place roughly 700 million years ago. A new breakthrough offers a glimpse into the molecular tools that may have enabled this colossal shift. </p>



<p>Scientists have just made a breakthrough achievement by successfully creating mouse stem cells from the genes of a single-celled life form.</p>



<h2 class="wp-block-heading" id="h-converting-stem-cells-into-a-live-mouse">Converting stem cells into a live mouse</h2>



<p>The feat is remarkable because stem cells have the unique ability to both self-replicate and transform into other cells with different functions. </p>



<p>The study reveals how scientists used lab-produced stem cells to form a living, breathing mouse from a developing embryo.</p>



<p>Perhaps what is even more surprising is that the genes facilitating this <a href="https://www.earth.com/news/blood-stem-cells-grown-in-the-lab-for-first-time-ever-leukemia-treatment/" target="_blank" rel="noreferrer noopener">stem cell</a> division and specialization were previously believed to be confined only within animals and not present in single-celled protists from a billion years ago.</p>



<p>"The molecular tool kit of stem cells is much older than we thought previously. These molecular tools are older than animal stem cells themselves," noted Ralf Jauch, a study author and a renowned stem cell biologist at the <a href="https://www.hku.hk" target="_blank" rel="noreferrer noopener">University of Hong Kong</a>. </p>



<p>This newfound understanding of natural evolution could pave the way for improved stem cell models and potentially combat diseases and aging.</p>



<h2 class="wp-block-heading" id="h-animals-and-protists-what-s-the-difference">Animals and protists: What's the difference?</h2>



<p>The difference between animals and protists goes beyond the number of cells. Protists, usually unicellular microscopic organisms that are not classified as animals, fungi, or plants, perform all functions within a single cell. </p>



<p>Meanwhile, animals are like master delegators, assigning cells to specific tasks, while other cells take care of different actions.</p>



<p>"We know that animals, most of them have stem cells because it’s something that you need. You need cells that can divide but at the same time give rise to other cells," explained Alex de Mendoza, a study author from <a href="https://www.qmul.ac.uk" target="_blank" rel="noreferrer noopener">Queen Mary University of London</a>.</p>



<h2 class="wp-block-heading" id="h-the-yamanaka-factors">The Yamanaka factors</h2>



<p>A fascinating discovery in 2012 by stem cell researcher Shinya Yamanaka revolutionized our understanding of stem cells. He found that adult cells could be transformed into stem cells by introducing four specific genes (Sox2, Pou5F1, Klf4, and Myc), coined as the Yamanaka factors.</p>



<p>This capability was initially considered exclusive to the animal kingdom since it seemed unnecessary in a unicellular organism. </p>



<p>However, de Mendoza and his colleagues recently discovered a few Yamanaka factors in the genomes of protists, challenging this belief.</p>



<h2 class="wp-block-heading" id="h-creating-mouse-cells-from-ancient-genes">Creating mouse cells from ancient genes</h2>



<p>The team located these genes in a protist about the size of a dust particle named a choanoflagellate. They replaced a Sox2 gene from a mouse with the similar gene found in the choanoflagellates, successfully reprogramming the cells to a stem cell state. </p>



<p>The mouse developed with characteristics from both its original embryo and the lab-induced stem cells.</p>



<p>However, not all the experiments succeeded. The introduction of the Pou gene, found in the choanoflagellate, to mouse cells, didn't induce stem cells. </p>



<p>This suggested that the Pou gene might have required more evolutionary modifications before it achieved its function in <a href="https://www.earth.com/news/experts-grow-models-of-human-embryos-in-the-lab-for-the-first-time/" target="_blank" rel="noreferrer noopener">modern animals</a>.</p>



<h2 class="wp-block-heading" id="h-reprogramming-of-mouse-cells">Reprogramming of mouse cells</h2>



<p>The successful reprogramming of mouse cells to a stem cell state through the introduction of a similar gene found in the choanoflagellates raises intriguing questions about the underlying mechanisms at play. </p>



<p>The researchers will not explore deeper to understand how these genetic factors interact with cellular processes to reprogram and transform cell identity.</p>



<p>By unraveling these intricate mechanisms, scientists aim to gain further insights into the potential applications of gene reprogramming in various fields, including <a href="https://www.earth.com/news/lab-grown-babies-revolutionary-science-or-ethical-disaster/" target="_blank" rel="noreferrer noopener">regenerative medicine</a> and developmental biology.</p>



<h2 class="wp-block-heading" id="h-implications-for-evolutionary-biology">Implications for evolutionary biology</h2>



<p>The discoveries made through this study on mouse stem cells have broad implications for both evolutionary biology and medical research.</p>



<p>By examining the shared genetic features between choanoflagellates and multicellular organisms, scientists can gain valuable knowledge about the evolutionary origins of complex traits and functions.</p>



<p>Understanding the ancient genetic toolkit employed by our ancestors can shed light on the development and diversification of life on Earth. </p>



<p>Furthermore, these findings have the potential to inform advancements in medical research, offering new avenues for studying cellular reprogramming and potentially unlocking novel therapeutic strategies for various diseases and conditions. </p>



<p>The synergistic combination of evolutionary insights and biomedical applications holds great promise for scientific innovation and improving human health.</p>



<h2 class="wp-block-heading" id="h-ancient-coding-for-a-modern-world">Ancient coding for a modern world</h2>



<p>De Mendoza suggests that choanoflagellates and our ancient ancestors may have used these gene capabilities to regulate basic functions, like cell proliferation. However, multicellular animals could have repurposed them to build complex bodies.</p>



<p>"<a href="https://www.earth.com/news/human-development-has-a-pause-button/" target="_blank" rel="noreferrer noopener">Evolution</a> doesn’t always need to invent. Usually, you use whatever you have, and then you build something new from mostly recycled parts," noted de Mendoza.</p>



<p>This research on mouse stem cells highlights the marvels of evolution and the intricate characteristics of our ancestors. It also demonstrates the power of human ingenuity, transforming genetic relics from the past into tools for scientific advancements today.</p>



<p>The study is published in the journal <em><a href="https://www.nature.com/articles/s41467-024-54152-x" target="_blank" rel="noreferrer noopener">Nature Communications</a></em>.</p>



<p>Image Credit: Gao Ya and Alvin Kin Shing Lee, with thanks to the Centre for Comparative Medicine Research (CCMR) for their support</p>



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Living mouse created with stem cells that predate animals

The great evolutionary leap from unicellular organisms to the animal...

<p></p>
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<p><br />
<span style="font-weight: 400;">Today&#8217;s </span><b>Video of the Day</b><span style="font-weight: 400;"> from </span><a href="https://www.nasa.gov/"><span style="font-weight: 400;">NASA</span></a><span style="font-weight: 400;"> describes the work of glaciologists, who study the evolution of ice in polar regions. </span></p>
<p><span style="font-weight: 400;">The flow of ice among glaciers varies over time and significantly affects the surrounding Earth systems, including the communities that are impacted by rising sea levels.</span></p>
<p><span style="font-weight: 400;">Scientists are working to determine the fate of the ice sheets in Greenland and Antarctica, in particular, to prepare for potential changes in the coming years.</span></p>
<p><span style="font-weight: 400;"> &#8212;</span></p>
<p><i><span style="font-weight: 400;">By </span></i><a href="http://csexton@earth.com"><i><span style="font-weight: 400;">Chrissy Sexton</span></i></a><i><span style="font-weight: 400;">, </span></i><a href="https://www.earth.com/staff/"><i><span style="font-weight: 400;">Earth.com</span></i></a><i><span style="font-weight: 400;"> Staff Writer</span></i></p>
<p><i><span style="font-weight: 400;">Video Credit: NASA</span></i></p>
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Understanding how ice sheets are evolving