<p>Today's Image of the Day from NASA Earth Observatory features South Korea, where a November storm set a new record for daily snowfall in Seoul.</p>



<p>“Wintry weather arrived in full force in South Korea. In the last week of November 2024, a storm brought record-breaking accumulations of snow to Seoul. The heavy snow disrupted travel and damaged structures in the nation’s capital and surrounding areas,” said <a href="https://earthobservatory.nasa.gov/images/153649/heavy-snows-in-korea" target="_blank" rel="noreferrer noopener">NASA</a>.</p>



<p>“On the morning of November 27, residents of Seoul awoke to 16.5 centimeters (6.5 inches) of new snow. That amount already surpassed the previous daily snowfall record for Seoul in November since records began in 1907, according to news reports.”</p>



<h2 class="wp-block-heading" id="h-snowfall-across-the-korean-peninsula-nbsp">Snowfall across the Korean Peninsula&nbsp;</h2>



<p>Yet, as NASA noted, the <a href="https://www.earth.com/news/secrets-of-snow-complexity-can-improve-winter-safety/">snow</a> kept flying. By the morning of November 28, Seoul had accumulated a total of 11.3 inches. About 22 miles to the south, the city of Suwon received 17 inches of snow.&nbsp;</p>



<p>“When clouds cleared the following day, the MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA’s Terra satellite captured this image, revealing a broad coating of white across the Korean Peninsula,” said NASA.</p>



<h2 class="wp-block-heading" id="h-rare-snowfall-event-in-south-korea-nbsp">Rare snowfall event in South Korea&nbsp;</h2>



<p>Meteorologists attributed this rare event to a sharp contrast between cold northern air and the warmer surface of the Yellow Sea.</p>



<p>Officials said that the temperature difference between the air and the <a href="https://www.earth.com/news/pacific-ocean-temperatures-highest-in-650-years-greatly-harming-coral-reefs/" target="_blank" rel="noreferrer noopener">sea surface</a> was more profound than normal due to unusual warmth in recent weeks, which likely contributed to the storm’s intensity.</p>



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



<p>“Those who braved the weather around Seoul witnessed landmarks transformed into a winter wonderland. However, the storm grounded hundreds of flights across the country, kept dozens of ferries in port, and snarled traffic,” said NASA.&nbsp;</p>



<p>“The weight of the snow also toppled trees and damaged greenhouses and other agricultural facilities in areas surrounding Seoul, according to reports.”</p>



<h2 class="wp-block-heading" id="h-snowfall-in-seoul-south-korea-nbsp">Snowfall in Seoul, South Korea&nbsp;</h2>



<p>Snowfall is not unusual in Seoul, but its frequency and accumulation levels are typically moderate. </p>



<p>Seoul has a temperate climate with cold, dry winters, and snow is a normal part of the season from December to February. However, heavy snowfall is rare, with most snowfalls being light to moderate.&nbsp;</p>



<p>The city averages about 25-30 days of snow per year, with a total accumulation that is far less than what is seen in colder regions of the world.</p>



<h2 class="wp-block-heading" id="h-climate-change-and-snowfall-patterns-nbsp">Climate change and snowfall patterns&nbsp;</h2>



<p><a href="https://www.earth.com/news/ski-resorts-face-snow-scarcity-due-to-climate-change/" target="_blank" rel="noreferrer noopener">Climate change</a> is altering snowfall patterns globally, with variations in both frequency and intensity - depending on the region. </p>



<p>Warmer average temperatures are shifting precipitation from snow to rain in many areas, particularly in low-lying regions and mid-latitudes. This trend reduces the duration and extent of <a href="https://www.earth.com/news/snow-cover-has-decreased-in-recent-decades/" target="_blank" rel="noreferrer noopener">snow cover</a>, especially at lower elevations. </p>



<p>However, paradoxically, some regions experience heavier snowstorms due to increased atmospheric moisture. Warmer air can hold more water vapor, leading to intense snowfall under the right conditions.</p>



<h3 class="wp-block-heading" id="h-complex-climate-impacts">Complex climate impacts</h3>



<p>In high-altitude and polar regions, the impact is more complex. Some areas, like the Himalayas and the Arctic, see diminished snowfall because of warmer conditions and melting ice.&nbsp;</p>



<p>Conversely, parts of the Arctic and Antarctica may experience <a href="https://www.earth.com/news/sea-ice-loss-increases-snowfall-over-west-antarctica/" target="_blank" rel="noreferrer noopener">increased snowfall</a> due to changes in wind patterns and enhanced evaporation over open waters caused by sea ice loss. </p>



<p>For example, in recent years, storms fueled by unusual temperature differentials have resulted in historic snowfalls in some areas, like the U.S. Northeast and parts of East Asia, as warmer oceans supply more moisture to cold air masses.</p>



<h3 class="wp-block-heading" id="h-shifts-in-the-seasons">Shifts in the seasons</h3>



<p>Seasonal timing is also shifting, with snowfalls occurring later in fall and ending earlier in spring. </p>



<p>These changes disrupt ecosystems that rely on consistent snowpacks, affect water resources dependent on snowmelt, and complicate winter activities such as agriculture and tourism.</p>



<p>Overall, the effects of climate change on snowfall are not uniform but are instead influenced by local geography, altitude, and changing weather systems.&nbsp;</p>



<p>As global temperatures continue to rise, these shifts are expected to intensify, requiring adaptation in water management, infrastructure, and disaster preparedness.</p>



<p>Image Credit: NASA Earth Observatory&nbsp;</p>



<p>-----</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.linkedin.com/in/eric-ralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and Earth.com.</p>



<p>-----</p>

Winter storm set a new snowfall record in Seoul, South Korea

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 NGC 1333, a reflection nebula located in the Perseus molecular cloud about 960 light-years away from Earth. The photo is a mosaic of images captured by the James Webb Space Telescope.</p>



<h2 class="wp-block-heading" id="h-the-power-of-webb-nbsp-nbsp">The power of Webb&nbsp;&nbsp;</h2>



<p>“Webb’s superb sensitivity allows astronomers to investigate young objects with extremely low masses. Some of the faintest ‘stars’ in the picture are in fact newly born free-floating brown dwarfs with masses comparable to those of giant planets,” noted <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>.</p>



<p>The same cluster was featured as the 33rd anniversary image of the Hubble Space Telescope in April 2023.&nbsp;</p>



<p>According to ESA, Hubble’s image just scratched the surface of this region, because clouds of dust obscure much of the star formation process. </p>



<p>"Observing with larger aperture and in the infrared part of the spectrum, Webb is capable of peering through the dusty veil to reveal newborn stars, brown dwarfs and planetary mass objects."</p>



<h2 class="wp-block-heading" id="h-webb-s-view-of-ngc1333">Webb’s view of NGC1333</h2>



<p>ESA noted that the center of the image presents a deep peek into the heart of the NGC1333 cloud.&nbsp;</p>



<p>“Across the image we see large patches of orange, which represent gas glowing in the infrared. These so-called Herbig-Haro objects form when ionized material ejected from young stars collides with the surrounding cloud. They are hallmarks of a very active site of star formation."</p>



<p>The disks of gas and dust that surround the <a href="https://www.earth.com/news/newly-discovered-stars-milky-way-are-old-as-universe/" target="_blank" rel="noreferrer noopener">stars</a> in this image may eventually produce planetary systems.&nbsp;</p>



<h2 class="wp-block-heading" id="h-formation-of-the-sun">Formation of the Sun</h2>



<p>“Similar to the young stars in this mosaic, our own Sun and planets formed inside a dusty molecular cloud, 4.6 billion years ago. Our Sun did not form in isolation but as part of a cluster, which was perhaps even more massive than NGC 1333,” explained ESA.</p>



<p>Over time, the stars in the Sun's birth cluster would have drifted apart due to gravitational interactions and the dispersion of gas in the region.</p>



<p>Astronomers have been studying certain clues, such as isotopic signatures in meteorites, that hint the Sun may have formed near massive stars. These stars likely produced supernovae, which could have influenced the early <a href="https://www.earth.com/news/mysterious-objects-spotted-in-the-outer-solar-system-beyond-pluto/" target="_blank" rel="noreferrer noopener">solar system</a> by injecting heavy elements like iron-60.</p>



<h2 class="wp-block-heading" id="h-star-formation-in-ngc-1333">Star formation in NGC 1333</h2>



<p>NGC 1333 is a vibrant example of a stellar nursery, where active <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> is ongoing. It is known for its chaotic appearance, shaped by the interactions between newborn stars and the surrounding material.</p>



<p>Within NGC 1333, astronomers have observed a high level of turbulence, which makes the region dynamic and complex. </p>



<p>These disturbances are caused by the outflows of young stars as they eject material into their surroundings, creating shock waves and influencing further star formation.&nbsp;</p>



<p>These outflows are often seen as jets, which are visible in multiple wavelengths of light, especially infrared, as the surrounding dust absorbs visible light.</p>



<h2 class="wp-block-heading" id="h-significance-of-ngc-1333">Significance of NGC 1333</h2>



<p>NGC 1333 is also an area of interest for studying the early stages of star and <a href="https://www.earth.com/news/planet-formation-new-insights-mechanics-physics/" target="_blank" rel="noreferrer noopener">planet formation</a>, as many of the stars within the cluster are in their infancy, still in the process of gathering material and developing protoplanetary disks.&nbsp;</p>



<p>In images, NGC 1333 is marked by bright patches of blue and red, representing reflection <a href="https://www.earth.com/news/six-rogue-worlds-discovered-inside-a-young-star-forming-nebula/" target="_blank" rel="noreferrer noopener">nebulae</a> and the ionized gas created by energetic young stars.&nbsp;</p>



<h2 class="wp-block-heading" id="h-the-perseus-molecular-cloud-nbsp">The Perseus molecular cloud&nbsp;</h2>



<p>The Perseus molecular cloud is a vast region of cold gas and dust located about 600 light-years away from Earth in the constellation <a href="https://www.earth.com/news/1500-billion-orphan-stars-discovered-in-the-perseus-galaxy-cluster/" target="_blank" rel="noreferrer noopener">Perseus</a>.&nbsp;</p>



<p>It is one of the most studied star-forming regions in our galaxy due to its relative proximity and the diversity of its young stellar objects. This cloud spans several hundred light-years and contains dense pockets of gas where new stars are actively forming.&nbsp;</p>



<p>These areas are often enshrouded in thick dust, which obscures them in visible light but allows astronomers to study them using infrared and radio wavelengths.</p>



<p>The Perseus molecular cloud is particularly interesting because of the chemistry taking place within it, including the formation of complex organic molecules that could be precursors to life.&nbsp;</p>



<p>Image Credit<strong>: </strong>ESA/Webb, NASA &amp; CSA</p>



<p>-----</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.linkedin.com/in/eric-ralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and Earth.com.</p>



<p>-----</p>

Stellar nursery shines in the Perseus cloud

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

<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>



<p>-----</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.linkedin.com/in/eric-ralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and Earth.com.</p>



<p>-----</p>

Webb unveils spiral galaxy NGC 2090 in magnificent detail

<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>



<p>-----</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.linkedin.com/in/eric-ralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and Earth.com.</p>



<p>-----</p>

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>



<p>-----</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.linkedin.com/in/eric-ralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and Earth.com.</p>



<p>-----</p>

Retreating glaciers and expanding meltwater lakes in Alaska

<p>Researchers have uncovered a connection between a specific type of body fat and the abnormal brain proteins associated with Alzheimer’s disease, detectable up to 20 years before the first signs of dementia.&nbsp;</p>



<p>This discovery, presented at the <a href="https://www.rsna.org/annual-meeting" target="_blank" rel="noreferrer noopener">Radiological Society of North America (RSNA) annual meeting</a>, highlights the potential for lifestyle interventions targeting this fat to influence Alzheimer’s development.</p>



<h2 class="wp-block-heading" id="h-early-detection-of-alzheimer-s-nbsp">Early detection of Alzheimer’s&nbsp;</h2>



<p>Study lead author Mahsa Dolatshahi is a postdoctoral research associate at the <a href="https://www.mir.wustl.edu/" target="_blank" rel="noreferrer noopener">Mallinckrodt Institute of Radiology</a> (MIR) at Washington University School of Medicine in St. Louis, Missouri.</p>



<p>“This crucial result was discovered because we investigated Alzheimer’s disease pathology as early as midlife - in the 40s and 50s - when the disease pathology is at its earliest stages, and potential modifications like weight loss and reducing visceral fat are more effective as a means of preventing or delaying the onset of the disease,” explained Dolatshahi.&nbsp;</p>



<p>With 6.9 million Americans over 65 currently living with Alzheimer’s - a figure projected to double by 2050 without medical breakthroughs - early interventions could significantly alter the trajectory of the <a href="https://www.earth.com/news/alzheimers-may-not-be-a-brain-disease/" target="_blank" rel="noreferrer noopener">disease</a>.</p>



<h2 class="wp-block-heading" id="h-lifestyle-factors-and-alzheimer-s-disease-nbsp">Lifestyle factors and Alzheimer’s disease&nbsp;</h2>



<p>The study examined how obesity, fat distribution, and metabolic factors contribute to Alzheimer’s pathology. It involved 80 cognitively normal middle-aged participants, with an average age of 49.4 years.&nbsp;</p>



<p>Among them, 57.5% were obese, with an average body mass index (BMI) of 32.31. Participants underwent brain PET scans, body MRI scans, metabolic assessments, and cholesterol analysis. MRI scans of the abdomen measured subcutaneous fat (fat beneath the skin) and <a href="https://www.earth.com/news/hidden-abdominal-fat-linked-to-alzheimers-disease/" target="_blank" rel="noreferrer noopener">visceral fat</a> (fat surrounding internal organs).</p>



<p>“We investigated the association of BMI, visceral fat, subcutaneous fat, liver fat fraction, thigh fat and muscle, as well as insulin resistance and HDL (good cholesterol), with amyloid and tau deposition in Alzheimer’s disease,” Dolatshahi said.</p>



<h2 class="wp-block-heading" id="h-visceral-fat-and-brain-protein-accumulation">Visceral fat and brain protein accumulation</h2>



<p>The team analyzed thigh muscle scans to assess fat and muscle volumes, while PET scans measured amyloid plaques and tau tangles - abnormal proteins linked to Alzheimer’s.</p>



<p>Their results showed that higher levels of visceral fat were strongly associated with amyloid accumulation, explaining 77% of the relationship between high BMI and amyloid buildup. Other fat types, such as subcutaneous fat, did not account for this link.</p>



<p>“Our study showed that higher visceral fat was associated with higher PET levels of the two hallmark pathologic proteins of Alzheimer’s disease - amyloid and tau,” Dolatshahi noted.&nbsp;</p>



<p>“To our knowledge, our study is the only one to demonstrate these findings at midlife where our participants are decades out from developing the earliest symptoms of the dementia that results from Alzheimer’s disease.”</p>



<h2 class="wp-block-heading" id="h-metabolic-health-and-alzheimer-s-risk">Metabolic health and Alzheimer’s risk</h2>



<p>The researchers found that increased insulin resistance and reduced HDL (good cholesterol) levels were linked to higher amyloid accumulation. Interestingly, higher HDL levels partially mitigated the impact of visceral fat on Alzheimer’s pathology.</p>



<p>“A key implication of our work is that managing Alzheimer’s risk in obesity will need to involve targeting the related metabolic and lipid issues that often arise with higher body fat,” explained senior study author Cyrus A. Raji, an associate professor of radiology at MIR.</p>



<h2 class="wp-block-heading" id="h-a-deeper-look-at-body-fat-distribution">A deeper look at body fat distribution</h2>



<p>While prior studies have linked high <a href="https://www.earth.com/news/weight-and-bmi-do-not-accurately-reflect-a-persons-health/" target="_blank" rel="noreferrer noopener">BMI</a> to brain health, this research is unique in distinguishing the effects of visceral fat from other types of body fat.</p>



<p>“This study goes beyond using BMI to characterize body fat more accurately with MRI and, in so doing, reveals key insights about why obesity can increase risk for Alzheimer’s disease,” Dolatshahi said.</p>



<h2 class="wp-block-heading" id="h-obesity-and-brain-blood-flow">Obesity and brain blood flow</h2>



<p>In a related study also presented at RSNA 2024, the team explored how <a href="https://www.earth.com/news/childhood-obesity-rates-are-surging-worldwide/" target="_blank" rel="noreferrer noopener">obesity</a> and visceral fat affect brain blood flow. Using MRI scans, researchers compared cerebral blood flow in individuals with high versus low visceral and subcutaneous fat. Those with high visceral fat exhibited reduced blood flow throughout the brain, while subcutaneous fat showed no significant impact.</p>



<p>“This work will have a considerable impact on public health because nearly three out of four Americans are overweight or obese,” said Raji.</p>



<p>‘Knowing that visceral obesity negatively affects the brain opens up the possibility that treatment with lifestyle modifications or appropriate weight-loss drugs could improve cerebral blood flow and potentially lower the burden of and reduce the risk for Alzheimer’s disease.”</p>



<p>-----</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.linkedin.com/in/eric-ralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and Earth.com.</p>



<p>-----</p>

Hidden body fat predicts Alzheimer’s 20 years before symptoms

Researchers have uncovered a connection between a specific type of...

<p>We've always considered ourselves unique, haven't we? But peel back the layers, and you'll find that humans, like all species, are bound by the threads of evolution. </p>



<p>One such thread is the instinct to come together when faced with external threats. The "common enemy effect" is&nbsp;a phenomenon in which we bond with others over a shared opponent or issue.</p>



<p>Humans do it, chimpanzees do it, and now we've learned that even our peaceful relatives, bonobos, exhibit this behavior in their own subtle way.&nbsp;At some point in their evolution, bonobos chose to make social bonding a priority.</p>



<h2 class="wp-block-heading" id="h-outgroup-threats-and-ingroup-cohesion">Outgroup threats and ingroup cohesion </h2>



<p>The discovery suggests that the link between outgroup threats and ingroup cohesion may have evolved several million years ago, before our evolutionary paths diverged.</p>



<p>The study was conducted by an international team of researchers led by <a href="https://www.kyoto-u.ac.jp/en" target="_blank" rel="noreferrer noopener">Kyoto University</a>. </p>



<p>They surmised that outgroup threats and ingroup cohesion may be an adaptation for group-based competition, a notion that has floated around since Darwin's days.</p>



<p>But they had a burning question - what about species that aren't known for their fierce inter-group rivalries? What about bonobos?</p>



<h2 class="wp-block-heading" id="h-bonobo-basics">Bonobo basics</h2>



<p>Bonobos are some of our closest primate relatives, sharing about 98.7% of their DNA with us humans. </p>



<p>These smart apes are known for their peaceful and cooperative social structures, which really sets them apart from their more <a href="https://www.earth.com/earthpedia-articles/chimpanzees-vs-bonobos-whats-the-difference/" target="_blank" rel="noreferrer noopener">aggressive chimpanzee cousins</a>.</p>



<p>They live in matriarchal societies where females take the lead, and they often use sexual behaviors to sort out conflicts and build social bonds. </p>



<p>With their slender bodies, dark faces, and pink lips, bonobos are pretty easy to tell apart from chimpanzees, and their expressive, human-like eyes show a lot of emotion and understanding.</p>



<p>Bonobos thrive by foraging for fruits, leaves, and small animals. They're naturally arboreal, spending plenty of time in the trees, but they’re also pretty skilled on the ground. </p>



<p>Lastly, they communicate using a mix of vocalizations, gestures, and facial expressions, showcasing their complex and sophisticated social intelligence.</p>



<h2 class="wp-block-heading" id="h-studying-evolution-of-bonobo-benevolence">Studying evolution of bonobo benevolence</h2>



<p>Picture this -- eight groups of bonobos spread across five sites in four countries, all part of an experiment designed to echo previous studies conducted with chimpanzees. </p>



<p>The process was simple -- expose the bonobos to vocalizations from <a href="https://www.earth.com/news/peaceful-bonobos-are-actually-more-aggressive-than-chimps/" target="_blank" rel="noreferrer noopener">other groups</a> and observe their reactions.</p>



<p>James Brooks, the study's lead author, was as curious as any of us. </p>



<p>"We had no idea how this would turn out. If the bond between group cohesion and outgroup competition wasn't adaptive due to the lack of lethal competition between groups, there would be no point," Brooks shared. </p>



<p>"But, if the effect had evolved before the human-chimpanzee-bonobo split, we might find some vestiges in modern bonobos."</p>



<p>The findings were startling yet insightful. The bonobos were clearly alert to the calls from outside groups, but their affiliation with their own group showed only a minor increase compared to chimpanzees.</p>



<p>Bonobos were seen sitting upright more and resting less, hinting at a slight increase in social grooming, a crucial behavior for reinforcing social bonds.</p>



<h2 class="wp-block-heading" id="h-social-dynamics-in-bonobos-evolution">Social dynamics in bonobos evolution</h2>



<p>The reactions of the bonobos during the study spark a fascinating discourse on social dynamics within their groups. </p>



<p>Unlike chimpanzees, who often exhibit heightened aggression in response to outgroup threats, bonobos are recognized for their relatively peaceful <a href="https://www.earth.com/news/bonobos-cooperation-challenges-beliefs-about-human-evolution/" target="_blank" rel="noreferrer noopener">interactions</a>. </p>



<p>This raises an intriguing question: how do these contrasting responses inform our understanding of social behavior in primates?</p>



<p>The study suggests that while awareness of external vocalizations exists, the bonobos maintain a subtle approach to group cohesion, prioritizing social bonding over defensive aggression. </p>



<p>This behavior may reflect an evolutionary strategy that emphasizes alliance-building in the face of potential threats, thereby fostering collaboration within rather than competition between groups.</p>



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



<p>The insights gained from this research extend well beyond the realm of academia; they carry significant implications for conservation efforts and our <a href="https://www.earth.com/news/social-theory-enemy-of-my-enemy-is-my-friend-proven-by-physics/" target="_blank" rel="noreferrer noopener">understanding of human behaviour</a>.</p>



<p>Recognizing that evolutionary traits from our primate relatives can inform why and how we interact socially underscores the importance of preserving species like the bonobo. </p>



<p>Their unique perspective on social interaction offers a valuable lens through which we can examine human responses to conflict and cooperation today. </p>



<p>As we navigate global challenges that require cross-cultural collaboration, appreciating the nuances of social behavior across species can illuminate pathways to strengthen our own communal ties and foster understanding in an increasingly interconnected world.</p>



<h2 class="wp-block-heading" id="h-bonobos-evolution-and-group-conflict">Bonobos evolution and group conflict</h2>



<p>The authors suggest that our shared ancestor, who roamed the earth 5–6 million years ago, might have experienced some group-based conflict. </p>



<p>But as the intensity decreased in the bonobos' evolutionary journey, so too did the strength of the effect.</p>



<p>"Although our research unearths deep roots of group conflict among our species, the real takeaway is that it can be overcome. And not just in isolated incidents, but on a species level," said Brooks.</p>



<p>Contrast this with other ape species -- <a href="https://www.earth.com/news/world-gorilla-day-supporting-the-guardians-of-the-forest/" target="_blank" rel="noreferrer noopener">gorillas</a>, <a href="https://www.earth.com/news/international-orangutan-day-2024-protecting-the-people-of-the-forest/" target="_blank" rel="noreferrer noopener">orangutans</a>, <a href="https://www.earth.com/news/world-chimpanzee-day-celebrating-our-closest-cousins/" target="_blank" rel="noreferrer noopener">chimpanzees</a>, <a href="https://www.earth.com/news/hidden-groups-of-skywalker-gibbons-found-through-their-love-songs/" target="_blank" rel="noreferrer noopener">gibbons</a>, and humans -- all of whom have been observed killing each other.</p>



<p>Bonobos seem to have found a way to break this vicious pattern. It's not just because they don't commit lethal aggression today, but more importantly, they somehow stopped doing it millions of years ago.</p>



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



<p>"Humans are capable of both: we can commit horrific acts to those we see as outside our group, but we're also capable of collaborating and working together across borders," said study senior author Shinya Yamamoto.</p>



<p>"Bonobos teach us that the ways our ancestors treated other groups does not seal our fate. Our own species has elements of both chimpanzee and bonobo <a href="https://www.earth.com/news/bonobos-are-more-interested-in-the-emotions-of-strangers/" target="_blank" rel="noreferrer noopener">group relations</a>, so it is crucial that we understand how both can, and have, evolved."</p>



<p>So next time you find yourself in a heated debate, think about our peaceful cousins, the bonobos. After all, they've proven that it's possible to adapt, evolve, and most importantly, choose peace over conflict.</p>



<p>The study is published in the journal&nbsp;<em><a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0307975" target="_blank" rel="noreferrer noopener">PLOS ONE</a>.</em></p>



<p>-----</p>



<p>Like what you read?&nbsp;<a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a>&nbsp;for engaging articles, exclusive content, and the latest updates.&nbsp;</p>



<p>Check us out on&nbsp;<a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by&nbsp;<a href="https://www.earth.com/author/eralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a>&nbsp;and Earth.com.</p>



<p>-----</p>

Bonobos are the only primates, including humans, that don't kill others in their species

We've always considered ourselves unique, haven't we? But peel back...

Many,Living,Earthworms,For,Fishing,In,The,Soil,,Background

<p>There's an invasion happening right under our feet, and most of us have no idea. Across North America, at least 70 imported, alien earthworm species are quietly altering our ecosystems, posing a largely overlooked threat.</p>



<p>That's where Elizabeth Hadly steps in. She's the Paul S. and Billie Achilles Professor at the <a href="https://humsci.stanford.edu/" target="_blank" rel="noreferrer noopener">Stanford School of Humanities and Sciences</a> and the senior author of a recent study on this very issue.</p>



<p>“Earthworms tell the story of the Anthropocene, the age we live in,” says Hadly. “It is a story of global homogenization of biodiversity by humans, which often leads to the decline of unique local species and the disruption of native ecosystem processes.”</p>



<p>They built the largest-ever database of these alien earthworms and warn that we need to better understand and manage these invaders.</p>



<h2 class="wp-block-heading" id="h-earthworms-friends-or-foes">Earthworms -- Friends or foes?</h2>



<p>Earthworms are nature’s ultimate recyclers, quietly working their magic beneath our feet. </p>



<p>These wriggly creatures belong to the <a href="https://www.earth.com/news/marine-worms-can-distinguish-sunlight-from-moonlight/" target="_blank" rel="noreferrer noopener">annelid family</a> and thrive in soil worldwide, except in places that are too cold or dry for their taste.</p>



<p>They come in a variety of sizes, ranging from tiny half-inch worms to some whoppers over 10 feet long (looking at you, giant Gippsland earthworm of Australia).</p>



<p>Most earthworms prefer moist, <a href="https://www.earth.com/news/electric-soil-esoil-boosts-crop-production-by-50-in-just-15-days/" target="_blank" rel="noreferrer noopener">nutrient-rich soil</a>, where they spend their days munching on organic matter like dead leaves, decomposing plants, and other goodies.</p>



<p>Since the late 1800s, people have brought earthworms to North America from places like Asia, Europe, South America, and Africa.</p>



<p>Sometimes, these introductions have boosted the agricultural economy. Other times, they've done more harm than good.</p>



<h2 class="wp-block-heading" id="h-how-earthworms-do-their-jobs">How earthworms do their jobs</h2>



<p>What’s cool about earthworms is their ability to transform dirt into fertile soil. </p>



<p>As they eat, they break down organic material and poop it out as castings, which are packed with nutrients that plants absolutely love.</p>



<p>They also create tiny tunnels as they burrow, which helps water and air flow through the soil -- essential for <a href="https://www.earth.com/news/soil-bacteria-makes-flowers-more-attractive-to-pollinators/" target="_blank" rel="noreferrer noopener">healthy plant roots</a>. </p>



<p>These little guys are underground architects and farmers, keeping ecosystems balanced without breaking a sweat.</p>



<h2 class="wp-block-heading" id="h-alien-earthworm-invasion-consequences">Alien earthworm invasion consequences</h2>



<p>These imported earthworms often consume aboveground leaf litter more aggressively than native species. </p>



<p>This change in the soil's surface can negatively impact native plants, amphibians, and insects. </p>



<p>In the northern broadleaf forests of the U.S. and Canada, alien earthworms stress trees like sugar maples by altering the soil's microhabitat. </p>



<p>This shift can set off a chain reaction, making it easier for invasive plants to spread.</p>



<p>Ironically, for a creature we associate with <a href="https://www.earth.com/news/ancient-amazonians-modified-the-soil-to-create-fertile-dark-earth/" target="_blank" rel="noreferrer noopener">improving soil</a>, some alien earthworms can actually degrade it. They may alter soil properties like nutrients, pH, and texture, leading to poorer quality crops.</p>



<h2 class="wp-block-heading" id="h-earthworm-biology">Earthworm biology</h2>



<p>Earthworms are also biologically fascinating. They breathe through their skin, so staying moist is a must for them. </p>



<p>They don’t have eyes, but they’re sensitive to light and vibrations, which helps them avoid predators.</p>



<p>Speaking of predators, they’re a favorite snack for birds, frogs, and even some mammals. And get this -- earthworms are hermaphrodites, meaning each worm has both male and female reproductive organs.</p>



<p>When they mate, they exchange sperm, and each worm can produce cocoons filled with eggs. It’s a pretty efficient way to keep the worm world thriving!</p>



<h2 class="wp-block-heading" id="h-why-alien-earthworms-are-winning">Why alien earthworms are winning</h2>



<p><a href="https://www.earth.com/news/growing-threat-of-invasive-species-requires-immediate-action/" target="_blank" rel="noreferrer noopener">Invasive species</a> of all kinds are a problem, but alien earthworms especially troublesome because they have some tricks up their sleeves. </p>



<p>Unlike most native species, many female alien earthworms can reproduce without needing a male. </p>



<p>On top of that, climate change is opening up new territories for them. As permafrost melts in northern areas void of native earthworms, these invaders find new places to thrive.</p>



<h2 class="wp-block-heading" id="h-eye-opening-numbers">Eye-opening numbers</h2>



<p>The research team built a database of native and alien earthworms using thousands of records from 1891 to 2021. They found alien earthworms in 97% of the soils they studied across North America. </p>



<p>These invaders represent 23% of the continent’s 308 earthworm species and account for 12 of the 13 most widespread species. </p>



<p>To put that in perspective, in the U.S., only 8% of fish species, 6% of mammals, and 2% of insects and arachnids <a href="https://www.earth.com/news/invasive-species-use-wildfires-and-drought-as-an-opening-to-move-in/" target="_blank" rel="noreferrer noopener">are alien</a>.</p>



<p>In Canada, the situation is even more striking. The proportion of alien earthworms is three times greater than that of native ones. </p>



<p>Across most of the lower 48 U.S. states and Mexico, there's about one alien earthworm for every two native species.</p>



<p>“These ratios are likely to increase because human activities facilitate the development of alien species that threaten native earthworm species, a phenomenon still largely overlooked,” says study lead author Jérôme Mathieu, an associate professor of ecology at the Sorbonne.</p>



<h2 class="wp-block-heading" id="h-why-do-these-alien-earthworms-matter">Why do these alien earthworms matter?</h2>



<p>To sum it all up, not all alien earthworms are troublemakers. But their widespread presence and unknown impacts on various ecosystems make them worth paying attention to. </p>



<p>The researchers suggest several solutions, like encouraging the use of native worms for composting and fishing bait, and early detection through regular monitoring and citizen science initiatives.</p>



<p>By shedding light on these little-known dynamics, the study highlights the vital roles earthworms play in <a href="https://www.earth.com/news/killing-animals-ecosystem-non-native-culling-harmful-strategy/" target="_blank" rel="noreferrer noopener">shaping ecosystems</a> and how they function in landscapes dominated by humans.</p>



<p>“This is most likely the tip of the iceberg,” says co-author <a href="https://www.researchgate.net/lab/John-Warren-Reynolds-Lab" target="_blank" rel="noreferrer noopener">John Warren Reynolds</a> of the Oligochaetology Laboratory and the New Brunswick Museum in Canada. </p>



<p>“Many other soil organisms may have been introduced, but we know very little about their impacts.”</p>



<p>Next time you're out in your garden or taking a walk in the woods, remember that there's a whole world beneath your feet that's more complicated than it seems. </p>



<p>Those wriggly worms might not just be helping your plants grow -- they could be part of a bigger story of ecological change that we're only beginning to understand.</p>



<p>----</p>



<p>The study was conducted by researchers from <a href="https://www.stanford.edu" target="_blank" rel="noreferrer noopener">Stanford University</a>, <a href="https://www.sorbonne-universite.fr/en" target="_blank" rel="noreferrer noopener">Sorbonne University</a>, and other institutions. </p>



<p>The full study was published in the journal <em><a href="https://www.nature.com/articles/s41559-023-02310-7" target="_blank" rel="noreferrer noopener">Nature Ecology &amp; Evolution</a></em>.</p>



<p>-----</p>



<p>Like what you read? <a href="https://www.earth.com/subscribe/" target="_blank" rel="noreferrer noopener">Subscribe to our newsletter</a> for engaging articles, exclusive content, and the latest updates.</p>



<p>Check us out on <a href="https://www.earth.com/earthsnap/" target="_blank" rel="noreferrer noopener">EarthSnap</a>, a free app brought to you by <a href="https://www.earth.com/author/eralls/" target="_blank" rel="noreferrer noopener">Eric Ralls</a> and Earth.com.</p>



<p>-----</p>

Alien earthworms are invading and harming ecosystems across North America

There's an invasion happening right under our feet, and most...

<p></p>
<div class="vdb_player vdb_58e3ebce955a315103d39bd158d96b98cd4fed198a0d2a49" vdb_params="m.embeded=cms_video_plugin_www.earth.com" data-placeholder="//img.vidible.tv/prod/2017-10/21/59ebcc6788420b5ead540075/59ebcc7c6174ba154e31fa6c_o_A_v2.jpg?w=1440&#038;h=900">	<script type="text/javascript" src="//delivery.vidible.tv/jsonp/pid=58e3ebce955a315103d39bd1/vid=59ebcc6788420b5ead540075/58d96b98cd4fed198a0d2a49.js?m.embeded=cms_video_plugin_www.earth.com"></script></div>
<p><br />
<span style="font-weight: 400;">Today’s </span><b>Video of the Day</b><span style="font-weight: 400;"> comes from the </span><a href="http://www.esa.int/"><span style="font-weight: 400;">European Space Agency</span></a><span style="font-weight: 400;"> (ESA) and features a look at the Sagaing Division in northwest Myanmar.</span></p>
<p><span style="font-weight: 400;">These images were captured by the Copernicus Sentinel-1A satellite and taken during a time of severe <a href="https://www.earth.com/image/severe-flooding-south-asia/">flooding</a>. The winding Chindwin River overflowed following a long monsoon season of heavy rains, which impacted up to a million people.</span></p>
<p><span style="font-weight: 400;"> &#8212;</span></p>
<p><i><span style="font-weight: 400;">By </span></i><a href="mailto:rarnold@earth.com"><i><span style="font-weight: 400;">Rory Arnold</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: </span></i><a href="http://www.esa.int/"><i><span style="font-weight: 400;">European Space Agency</span></i></a></p>

The Sagaing Division in Myanmar