<p>Today's <strong>Image of the Day</strong> from the <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">European Space Agency</a> 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 ESA.</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>"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>. </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, which 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. Elements heavier than helium are created in the cores of stars and 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>



<h2 class="wp-block-heading" id="h-process-of-star-formation">Process of star formation</h2>



<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. 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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NGC 604 is home to hundreds of hot, massive stars

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

<p>Today's <strong>Image of the Day</strong> from the <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">European Space Agency</a> features the Little Dumbbell Nebula, also known as Messier 76, located in the constellation Perseus 3,400 light-years away from Earth.</p>



<p>Astronomers captured this new image of the Little Dumbbell Nebula to commemorate the 34th anniversary of the Hubble Space Telescope, a joint venture between NASA and the European Space Agency (ESA).</p>



<p>The snapshot provides not only a breathtaking view but also deep insights into the life cycle of <a href="https://www.earth.com/news/dark-stars-scientists-discover-a-new-type-of-star-powered-by-dark-matter/" target="_blank" rel="noreferrer noopener">stars</a> and the dynamic processes within nebulae.</p>



<h2 class="wp-block-heading" id="h-understanding-messier-76">Understanding Messier 76</h2>



<p>Messier 76 is categorized as a planetary nebula, a term which historically arises from its round, planet-like appearance when viewed through early, low-power telescopes. However, the term is somewhat misleading as planetary nebulae have no connection to actual <a href="https://www.earth.com/news/nasa-finds-17-exoplanets-that-have-oceans-and-possibly-alien-life/" target="_blank" rel="noreferrer noopener">planets</a>. </p>



<p>Instead, they represent an expansive shell of luminous gases expelled by a dying red giant star, which subsequently collapses into a dense, hot white dwarf. This transformation marks the late stages of stellar evolution for medium to low-mass stars.</p>



<h2 class="wp-block-heading" id="h-structure-of-messier-76">Structure of Messier 76</h2>



<p>The structure of Messier 76 is particularly notable. It comprises a central ring - viewed edge-on - giving the appearance of a bar-like feature, with two distinct lobes emanating from either side. This formation is believed to be the result of materials ejected by the star during its red giant phase, possibly sculpted by interactions with a companion star.&nbsp;</p>



<p>Although this binary companion is not visible in current Hubble images, its presence is inferred from the thick disk of dust and gas aligned with its orbital plane. The phenomenon of the companion star potentially being absorbed by the primary star, a process akin to stellar cannibalism, is a captivating aspect of the nebula's history.</p>



<h2 class="wp-block-heading" id="h-the-dynamic-environment-of-the-nebula">The dynamic environment of the nebula</h2>



<p>At the core of the nebula, the primary star, now collapsing into a <a href="https://www.earth.com/news/white-dwarf-stars-may-be-billions-of-years-older-than-estimated/" target="_blank" rel="noreferrer noopener">white dwarf</a>, reaches extreme temperatures, estimated at a scorching 120,000 degrees Celsius - about 24 times hotter than the surface of our Sun. </p>



<p>This intensely hot remnant is visible as a small, bright point at the center of the nebula. Directly below this, another star can be seen; however, it is merely aligned with the nebula by chance and is not a part of it.</p>



<p>The dynamics within Messier 76 are driven by powerful forces. The central disk seems to constrict the material, creating two lobes of gas escaping along the rotational axis of the star, perpendicular to the disk.&nbsp;</p>



<p>The lobes are propelled outward by a potent stellar wind, moving at a staggering two million miles per hour. This rapid movement is sufficient to travel the distance from Earth to the <a href="https://www.earth.com/news/timeless-mystery-solved-scientists-uncover-what-is-inside-the-moons-core/" target="_blank" rel="noreferrer noopener">Moon</a> in just over seven minutes. </p>



<p>The collision of the fast-moving gas with older, slower-moving material ejected during the star’s red giant phase results in the stunning glowing effect seen in the nebula. The glow, ignited by the ultraviolet radiation from the white dwarf, is a spectacle of colors with red emanating from nitrogen and blue from oxygen.</p>



<h2 class="wp-block-heading" id="h-a-cosmic-moment-in-time">A cosmic moment in time</h2>



<p>Despite its current brilliance, the existence of the Little Dumbbell Nebula is fleeting on a cosmological scale, expected to last only about 15,000 years - a mere moment in the lifespan of the <a href="https://www.earth.com/news/dark-energy-is-ripping-the-universe-apart-but-we-arent-sure-how/" target="_blank" rel="noreferrer noopener">universe</a>. </p>



<p>This brief period highlights the transient nature of such cosmic phenomena, which, while short-lived, provide crucial insights into the mechanics of stellar evolution and the complex interactions within these celestial sculptures.</p>



<h2 class="wp-block-heading" id="h-more-about-messier-76">More about Messier 76</h2>



<p>Messier 76 was discovered by Pierre Méchain in 1780. It was later cataloged by Charles Messier, who included it in his famous list of nebulous objects.</p>



<p>The nebula's faintness and small size require a good telescope to be observed effectively, with larger telescopes able to reveal more of its fine details and structure.</p>



<p>Studying objects like Messier 76 helps astronomers understand the life cycle of stars and the processes that occur during the late stages of stellar evolution. The materials expelled by planetary nebulae like Messier 76 eventually contribute to the interstellar medium, from which new stars and planetary systems may form.</p>



<p>Image Credit: ESA Space Agency </p>



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Cosmic cannibalism and stellar winds: Unveiling the secrets of Messier 76 

<p>Today's Image of the Day from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features a vibrant and detailed depiction of the Gulf of Oman. The image was captured on March 17, 2024 by the primary sensor on the PACE satellite. </p>



<h2 class="wp-block-heading" id="h-pace-satellite-nbsp">PACE satellite&nbsp;</h2>



<p>NASA launched the PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite aboard a SpaceX Falcon 9 rocket on February 8, 2024. The mission marks a significant advancement in our ability to study Earth’s oceanic and atmospheric systems.&nbsp;</p>



<p>The PACE satellite is equipped with a state-of-the-art Ocean Color Instrument (OCI), designed to capture intricate details of ocean phenomena that are often invisible to the naked eye. This technology aims to provide new insights into the complex interactions between the <a href="https://www.earth.com/news/good-news-ocean-oxygen-loss-may-ultimately-reverse/" target="_blank" rel="noreferrer noopener">ocean</a> and the atmosphere.</p>



<h2 class="wp-block-heading" id="h-compelling-visual-data-nbsp">Compelling visual data&nbsp;</h2>



<p>Less than two months after its launch, the PACE satellite has already begun delivering compelling visual data, thanks to the efforts of NASA engineer Joseph Knuble and his team. Knuble, who serves as the lead instrument systems engineer for OCI, compiled a remarkable gallery of 36 images.</p>



<p>This standout image of the Gulf of Oman has been crafted using a combination of red, green, and blue wavelengths of light, specifically at 630, 532, and 465 nanometers, respectively.</p>



<h2 class="wp-block-heading" id="h-enhanced-image-of-the-gulf-of-oman">Enhanced image of the Gulf of Oman</h2>



<p>The image Knuble selected is not a natural-color representation but an enhanced one designed to highlight specific details within the water.&nbsp;</p>



<p>This technique allows for a more vivid portrayal of oceanic features, such as the swirling bands of a <a href="https://www.earth.com/news/phytoplankton-remain-surprisingly-active-underneath-arctic-sea-ice/" target="_blank" rel="noreferrer noopener">phytoplankton</a> bloom. Jeremy Werdell, PACE project scientist at NASA’s Goddard Space Flight Center, noted: "The image highlights the beauty and complexity of that area."</p>



<h2 class="wp-block-heading" id="h-phytoplankton-bloom-in-the-gulf-of-oman-nbsp">Phytoplankton bloom in the Gulf of Oman&nbsp;</h2>



<p>Phytoplankton blooms, like the one visible in the Gulf of Oman, occur when environmental conditions - such as light availability and nutrient levels - are favorable, leading to rapid growth. These blooms can have significant ecological impacts.&nbsp;</p>



<p>The swirls of green seen in the image likely include Noctiluca scintillans, a type of marine dinoflagellate known for its striking appearances. However, despite their beauty, Noctiluca blooms can deplete <a href="https://www.earth.com/news/cautionary-tale-todays-ocean-oxygen-levels-may-have-cascading-impacts/" target="_blank" rel="noreferrer noopener">oxygen levels</a> in the water, resulting in hypoxia and creating dead zones that severely impact marine life.</p>



<h2 class="wp-block-heading" id="h-changing-dynamics-in-the-arabian-sea-nbsp">Changing dynamics in the Arabian Sea&nbsp;</h2>



<p>The changing dynamics in the Arabian Sea are also noteworthy. Historically rich in diatoms, vital components of the marine food chain, the region now sees a dominance of Noctiluca. This shift could be attributed to changes in water stratification and nutrient availability, with Noctiluca thriving under conditions that are less favorable for diatoms.</p>



<p>One of the groundbreaking aspects of the OCI is its ability to detect hundreds of different wavelengths of light. This capability is not just about capturing beautiful images; it provides a critical tool for identifying and differentiating between various types of phytoplankton from space. Previously, such determinations could only be made through direct water samples.</p>



<h2 class="wp-block-heading" id="h-tracking-the-health-of-marine-ecosystems-nbsp">Tracking the health of marine ecosystems&nbsp;</h2>



<p>The PACE mission is poised to transform our understanding of oceanic and atmospheric interactions. By providing detailed, high-resolution images and data, the satellite will enable scientists to monitor environmental changes, track the health of <a href="https://www.earth.com/news/overfishing-and-habitat-degradation-have-devastated-marine-ecosystems/" target="_blank" rel="noreferrer noopener">marine ecosystems</a>, and better understand the global climate system. </p>



<p>This mission highlights the importance of continued investment in space technology and research, offering a clearer view of our planet's intricate and changing natural systems.</p>



<h2 class="wp-block-heading" id="h-gulf-of-oman">Gulf of Oman</h2>



<p>The Gulf of Oman is a strategically significant body of water located in the Middle East, connecting the Arabian Sea with the Strait of Hormuz, which then leads into the Persian Gulf. This gulf borders several countries including Iran, Oman, Pakistan, and the United Arab Emirates, making it a crucial geographic and economic zone.</p>



<h3 class="wp-block-heading" id="h-transportation-nbsp">Transportation&nbsp;</h3>



<p>The Gulf of Oman is particularly important for its role in global oil transportation. A large percentage of the world's petroleum, as it is shipped from the oil-rich countries of the Persian Gulf, passes through the Strait of Hormuz into the Gulf of Oman and then to various destinations across the globe.&nbsp;</p>



<p>This makes the area not only economically significant but also a hot spot for geopolitical tensions and security concerns.</p>



<h3 class="wp-block-heading" id="h-marine-ecosystems-nbsp">Marine ecosystems&nbsp;</h3>



<p>Ecologically, the Gulf of Oman is diverse, hosting various species of <a href="https://www.earth.com/news/ocean-noise-is-getting-louder-what-does-this-mean-for-animals/" target="_blank" rel="noreferrer noopener">marine life</a> which support local fishing communities. However, the area faces environmental challenges, including the risk of oil spills and the impacts of industrialization and maritime traffic which threaten its marine ecosystems.</p>



<h3 class="wp-block-heading" id="h-cultural-history-nbsp">Cultural history&nbsp;</h3>



<p>Additionally, the Gulf of Oman has a rich cultural history, influenced by the various civilizations that have inhabited its shores and traded across its waters. This history is reflected in the diverse cultures of the region today, making it a place of significant cultural heritage.</p>



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



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The Gulf of Oman in the Middle East

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

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the Bermejo River and the Río Grande de Tarija, which flow through Argentina and Bolivia in South America. The photograph was captured by an astronaut onboard the International Space Station.</p>



<h2 class="wp-block-heading" id="h-meandering-rivers">Meandering rivers</h2>



<p>“The meandering rivers in this image are sourced in the Andes Mountains and generally flow southeast through valleys in the foothills - the region between the high mountains and plains. The Iruya River deposits particles of silt and clay as it flows into the valley centered in this image,” said NASA.</p>



<p>“Visible indications of the rivers’ shifting channels include river islands, point bars (on the inside curve of streams), and several meander scars. Such scars form when a river gets cut off from the main flow and fills in with sediment, soil, and vegetation.”</p>



<p>“Sediment from the adjacent highlands filled valleys that were formed by tectonic forces driving uplift of the Andes. These deposits are subsequently carried by rivers, such as the Iruya, along with new sediment to form the light-toned braided channels and the adjacent darker-toned floodplains. Nutrient-rich floodplain soils provide fertile ground for agricultural fields.”</p>



<h2 class="wp-block-heading" id="h-bermejo-river">Bermejo River</h2>



<p>The Bermejo River originates in the Bolivian <a href="https://www.earth.com/news/biodiversity-hotspots-are-shrinking-in-the-andes-mountains/" target="_blank" rel="noreferrer noopener">Andes</a> and flows into Argentina. It plays a crucial role in the geographical and ecological landscape of the region. The river's course is characterized by its meandering path through the Gran Chaco plain, making it a significant river in the region's hydrological system.</p>



<h3 class="wp-block-heading" id="h-economic-importance">Economic importance</h3>



<p>The Bermejo River is vital for agriculture, providing essential water resources for irrigation. It also has potential for hydroelectric power generation.</p>



<h3 class="wp-block-heading" id="h-biodiversity-nbsp">Biodiversity&nbsp;</h3>



<p>The diverse habitats created by the Bermejo River, including its riverbanks, floodplains, and adjacent forests, support rich biodiversity. However, the wildlife in this region faces threats from habitat destruction, pollution, and climate change, making conservation efforts critical for their survival.</p>



<p><a href="https://www.earth.com/news/jaguars-in-the-amazon-are-threatened-by-climate-extremes/" target="_blank" rel="noreferrer noopener">Jaguars</a> are the apex predators of this region, and are occasionally spotted along the riverbanks, where they hunt. Large, herbivorous mammals called tapirs are found in the forests around the Bermejo River. They often visit the river to drink and cool off.</p>



<p>Capibaras, the world’s largest rodents, are commonly found in the wetlands and along the river edges.</p>



<p>Jabirus, the tallest flying birds in South and Central America, can often be seen in wetlands along the Bermejo River. Toco toucans, known for their colorful bills, can be found in the forested areas near the river.</p>



<h2 class="wp-block-heading" id="h-rio-grande-de-tarija">Río Grande de Tarija</h2>



<p>The Río Grande de Tarija, also known in its lower stretches as the Guadalquivir, flows primarily within Bolivia. It is a critical watercourse in the Tarija Department, contributing significantly to the region's agriculture and livelihoods.</p>



<h3 class="wp-block-heading" id="h-economic-importance-0">Economic importance</h3>



<p>This river is essential for irrigation, supporting a variety of crops and contributing to the local economy. The surrounding lands are fertile and productive, thanks to the river's water.</p>



<h3 class="wp-block-heading" id="h-challenges">Challenges</h3>



<p>Similar to other rivers, the Río Grande de Tarija faces challenges such as water management issues, <a href="https://www.earth.com/news/predicting-the-effects-of-pollutants-on-river-ecosystems/" target="_blank" rel="noreferrer noopener">pollution</a>, and the impacts of climate change on its flow and health.</p>



<h3 class="wp-block-heading" id="h-wildlife-in-bolivian-rivers">Wildlife in Bolivian rivers</h3>



<p>River basins in Bolivia are home to a wide range of bird species, including various species of herons, egrets, kingfishers, and perhaps even some rarer species like the wattled jacana or the sunbittern. The diverse birdlife is attracted to the abundance of fish and the relatively untouched natural habitats along the river.</p>



<p>The Characidae family includes many fish species that are commonly found in South American rivers, such as tetras. They are known for their diversity and are a key part of the river's ecosystem, serving as both <a href="https://www.earth.com/news/diving-to-extremes-predatory-fish-frequent-the-oceans-twilight-zone/" target="_blank" rel="noreferrer noopener">predator</a> and prey.</p>



<p>Cichlids are another diverse group of fish that can be found in South American rivers. They play significant roles in their ecosystems as both predators and herbivores.</p>



<p>The rivers of Bolivia are also home to various catfish species, which are well adapted to life in muddy and turbulent waters. These include the armored catfish, which are often found clinging to rocks and logs.</p>



<p>Image Credit: NASA Earth Observatory/ ISS Crew Earth Observations Facility/ Earth Science and Remote Sensing Unit, Johnson Space Center</p>



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

The Río Grande de Tarija and Bermejo River in South America

<p>Today's <strong>Image of the Day</strong> from the <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">European Space Agency</a> features the Columbia Glacier, a tidewater glacier located in Prince William Sound on the south coast of Alaska. It is one of the most rapidly changing <a href="https://www.earth.com/news/melting-glaciers-pose-great-threat-to-biodiversity-in-mountain-ranges/" target="_blank" rel="noreferrer noopener">glaciers</a> in the world and has been closely studied for the insights it provides into glacial mechanics and climate change impacts. </p>



<p>"Since the early 1980s, the Columbia Glacier has retreated more than 20 km and lost about half of its total volume. This one glacier accounts for nearly half of the ice lost in the Chugach Mountains," noted ESA.</p>



<p>"The changing climate is thought to have caused its retreat. Until 1980, when its rapid and constant retreat began, the glacier’s terminus was observed at the northern edge of Heather Island, which lies near the end of Columbia Bay, the inlet into which the glacier currently flows before draining into Prince William Sound."</p>



<p>"This satellite image, acquired in September 2023, shows instead the deep mostly ice-free Columbia Bay dotted with numerous icebergs and fragmented sea-ice."</p>



<h2 class="wp-block-heading" id="h-dramatic-calving-events">Dramatic calving events</h2>



<p>The Columbia Glacier is known for its dramatic calving events, where large chunks of ice break off from the glacier's terminus and fall into the sea, becoming icebergs. This process has been particularly active as the glacier has retreated, contributing to hazards for shipping in Prince William Sound.</p>



<p>The glacier has been the focus of extensive scientific research, serving as a case study for understanding the dynamics of tidewater glaciers and their responses to <a href="https://www.earth.com/news/preparing-for-ocean-acidification-a-silent-killer-of-climate-change/" target="_blank" rel="noreferrer noopener">climate change</a>. Studies have used satellite imagery, field observations, and modeling to track its changes over time.</p>



<h2 class="wp-block-heading" id="h-climate-impact-on-the-columbia-glacier">Climate impact on the Columbia Glacier</h2>



<p>"Columbia is just one of the many glaciers suffering from the effects of climate change. Most of the glaciers around the world are losing mass. However, before the advent of satellites, measuring their retreat and studying their vulnerability to climate change was difficult considering their size, remoteness and rugged terrain they occupy," said ESA.</p>



<p>"Different satellite instruments now can gather information systematically and over large areas, providing an effective means to monitor change, keep track of all calving stages and quantify the melting rate and their contribution to sea-level rise."</p>



<h2 class="wp-block-heading">More about Columbia Glacier&nbsp;</h2>



<p>Columbia Glacier flows from the Chugach Mountains into Columbia Bay. It was once one of the largest contributors to <a href="https://www.earth.com/news/sea-level-rise-will-cost-coastal-cities-over-1-trillion-in-damages/" target="_blank" rel="noreferrer noopener">sea level rise</a> due to its significant ice loss. </p>



<p>The glacier's dynamics are influenced by its interaction with water, where the terminus meets the ocean. As the glacier flows into the sea, large chunks of ice calve off the front, leading to dramatic scenes of ice crashing into the <a href="https://www.earth.com/news/shelf-sediment-ocean-composition/" target="_blank" rel="noreferrer noopener">ocean</a>. This process has been intensifying due to warmer temperatures and changes in water circulation, which undermine the ice from below.</p>



<p>Columbia Glacier's retreat has significant implications for marine navigation and local ecosystems. The increase in icebergs calving into the bay poses hazards to ships, while the fresh meltwater impacts local water temperatures and salinity, affecting the habitat of fish and other marine life.</p>



<h2 class="wp-block-heading">Melting glaciers and ocean composition&nbsp;</h2>



<p>Glaciers, which are large masses of accumulated snow and ice, store about 69 percent of the world's fresh water. As the climate warms, these glaciers increasingly melt and release freshwater into nearby seas and the ocean at large.</p>



<h3 class="wp-block-heading">Influx of freshwater</h3>



<p>This influx of freshwater from <a href="https://www.earth.com/news/melting-glaciers-pose-great-threat-to-biodiversity-in-mountain-ranges/" target="_blank" rel="noreferrer noopener">melting glaciers</a> alters the salinity (salt concentration) of the ocean water. Since freshwater is less dense than saltwater, its addition can lead to stratification in which lighter, less salty water layers on top of denser, saltier water. </p>



<p>This stratification can disrupt ocean currents, which are driven in part by differences in water density and temperature. These currents are crucial for regulating global climate by distributing heat and nutrients around the planet.</p>



<h3 class="wp-block-heading">Changes in salinity&nbsp;</h3>



<p>Furthermore, changes in <a href="https://www.earth.com/news/human-induced-changes-in-ocean-salinity-threaten-biodiversity-and-marine-ecosystems/" target="_blank" rel="noreferrer noopener">salinity</a> can affect marine life, which often has narrow salinity tolerance ranges. For example, shifts in salinity can impact breeding cycles, migration patterns, and the availability of nutrients. </p>



<h3 class="wp-block-heading">Global carbon cycle</h3>



<p>As the ocean's composition changes, its capacity to absorb carbon dioxide from the atmosphere could also be altered, affecting the global carbon cycle and, by extension, climate change feedback mechanisms.</p>



<p>The melting of glaciers contributes to more pronounced changes in ocean conditions, impacting everything from global climate systems to local ecosystems in marine environments.</p>



<p>Image Credit: ESA&nbsp;</p>



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Columbia Glacier on the south coast of Alaska

"Severe Solar Storm" warning as Earth prepares for impact from seven CMEs

Update -- May 10, 2024 at 5:51 PM EDT NOAA...

<p>In a remarkable feat, a team of scientists has taken the world's first X-ray signature of just one atom. This stunning achievement could revolutionize the way scientists <a href="https://www.earth.com/news/quantum-realm-vibrating-atoms-tune-single-electron-energy/" target="_blank" rel="noreferrer noopener">detect materials</a>.</p>



<p>The research team was led by <a href="https://www.ohio.edu/cas/hla" target="_blank" rel="noreferrer noopener">Saw Wai Hla</a>, Professor of Physics at Ohio University and scientist at <a href="https://www.anl.gov/" target="_blank" rel="noreferrer noopener">Argonne National Laboratory</a>.</p>



<h2 class="wp-block-heading" id="h-atoms-and-the-evolution-of-x-ray-technology">Atoms and the evolution of X-ray technology</h2>



<p>Since its discovery by Roentgen in 1895, X-rays have been used in various applications, from medical examinations to security screenings in airports. Even NASA's Mars rover, <a href="https://www.earth.com/news/nasas-curiosity-rover-records-a-martian-day-from-dawn-to-dusk/" target="_blank" rel="noreferrer noopener">Curiosity</a>, is equipped with an X-ray device to examine the materials composition of rocks on Mars.</p>



<p>Over the years, advancements in synchrotron X-ray sources and new instruments have greatly reduced the quantity of materials required for X-ray detection. </p>



<p>However, until now, the smallest amount one could X-ray a sample was in attogram, which is about 10,000 atoms or more. This limitation was due to the extremely weak X-ray signal produced by an atom, making it undetectable by conventional X-ray detectors.</p>



<h2 class="wp-block-heading" id="h-realizing-a-long-standing-dream">Realizing a long-standing dream</h2>



<p>According to Hla, it has been a long-standing dream of scientists to X-ray just one atom, which is now being realized by his research team. </p>



<p>"Atoms can be routinely imaged with scanning probe microscopes, but without X-rays one cannot tell what they are made of. We can now detect exactly the type of a particular atom, one atom-at-a-time, and can simultaneously measure its chemical state," explained Hla, who is also the director of the Nanoscale and Quantum Phenomena Institute at <a href="https://www.ohio.edu/cas/nqpi" target="_blank" rel="noreferrer noopener">Ohio University</a>. </p>



<p>"Once we are able to do that, we can trace the materials down to the ultimate limit of just one atom. This will have a great impact on environmental and medical sciences and maybe even find a cure that can have a huge impact for humankind. This discovery will transform the world," Hla continued.</p>



<h2 class="wp-block-heading" id="h-how-to-x-ray-a-single-atom">How to x-ray a single atom</h2>



<p>The research team used a purpose-built synchrotron X-ray instrument at the XTIP beamline of Advanced Photon Source and the Center for Nanoscale Materials at Argonne National Laboratory. They chose an iron atom and a terbium atom, both inserted in respective molecular hosts, for demonstration. </p>



<p>To detect the X-ray signal of one atom, the team supplemented conventional detectors in X-rays with a specialized detector made of a sharp metal tip positioned at extreme proximity to the sample to collect X-ray excited electrons. This is a technique known as synchrotron X-ray scanning tunneling microscopy or SX-STM.</p>



<p>"The technique used, and concept proven in this study, broke new ground in X-ray science and <a href="https://www.earth.com/news/golds-glow-luminescence-caused-quantum-realm-effects/" target="_blank" rel="noreferrer noopener">nanoscale</a> studies," said Tolulope Michael Ajayi, the first author of the paper and a Ph.D. student working on this project as part of his thesis. </p>



<p>"More so, using X-rays to detect and characterize individual atoms could revolutionize research and give birth to new technologies in areas such as quantum information and the detection of trace elements in environmental and medical research, to name a few. This achievement also opens the road for advanced materials science instrumentation," Ajayi concluded.</p>



<h2 class="wp-block-heading" id="h-decade-of-collaboration-ends-with-success">Decade of collaboration ends with success</h2>



<p>Hla has been involved in the development of an SX-STM instrument and its measurement methods for the last 12 years, together with Volker Rose, a scientist at the Advanced Photon Source at Argonne National Laboratory. </p>



<p>"I have been able to successfully supervise four OHIO graduate students for their Ph.D. theses related to SX-STM method development over a 12-year period. We have come a long way to achieve the detection of a single atom X-ray signature," Hla said.</p>



<h2 class="wp-block-heading" id="h-investigating-environmental-effects-on-rare-earth-atoms">Investigating environmental effects on rare-Earth atoms</h2>



<p>In addition to achieving the X-ray signature of one atom, the team's key goal was to use this technique to investigate the environmental effect on a single rare-earth atom. </p>



<p>"We have detected the chemical states of individual atoms as well," Hla explained. "By comparing the chemical states of an iron atom and a terbium atom inside respective molecular hosts, we find that the terbium atom, a <a href="https://www.earth.com/news/rare-earth-elements-are-waiting-to-be-discovered-in-waste/" target="_blank" rel="noreferrer noopener">rare-earth metal</a>, is rather isolated and does not change its chemical state while the iron atom strongly interacts with its surrounding."</p>



<p><a href="https://www.earth.com/news/earths-mantle-may-contain-a-wealth-of-green-metals/" target="_blank" rel="noreferrer noopener">Rare-earth</a> materials are extremely important in creating and advancing technology, and are used in everyday devices such as cell phones, computers, and televisions. </p>



<p>Through this discovery, scientists can now identify not only the type of element but its chemical state as well, allowing them to better manipulate atoms inside different materials hosts to meet ever-changing needs in various fields.</p>



<h2 class="wp-block-heading" id="h-connecting-synchrotron-x-rays-with-quantum-tunneling">Connecting synchrotron X-rays with quantum tunneling</h2>



<p>Moreover, the research team has also developed a new method called "X-ray excited resonance tunneling or X-ERT" that allows them to detect how orbitals of a single molecule orient on a material surface using synchrotron X-rays. </p>



<p>"This achievement connects synchrotron X-rays with <a href="https://www.earth.com/news/molecules-scramble-quantum-information-equally-well-black-holes/" target="_blank" rel="noreferrer noopener">quantum tunneling</a> process to detect X-ray signature of an individual atom and opens many exciting research directions including the research on quantum and spin (magnetic) properties of just one atom using synchrotron X-rays," Hla excitedly concluded.</p>



<h2 class="wp-block-heading" id="h-atoms-x-rays-and-future-technology">Atoms, x-rays and future technology</h2>



<p>In summary, the incredible feat of capturing the first-ever X-ray signature of a single atom marks a significant milestone in the field of X-ray science and <a href="https://www.earth.com/news/stunning-discovery-first-evidence-of-a-self-healing-metal/" target="_blank" rel="noreferrer noopener">nanoscale studies</a>. </p>



<p>This achievement, made possible by the dedicated efforts of a collaborative research team led by Professor Saw Wai Hla, opens up a world of possibilities for scientific research and technological advancements. </p>



<p>By pushing the boundaries of what was previously thought to be undetectable, this innovative technique has the potential to revolutionize various fields, from environmental and medical sciences to quantum information and advanced materials science instrumentation. </p>



<p>As scientists continue to explore the capabilities of this powerful tool, they pave the way for discoveries that could have a profound impact on our understanding of the world at the atomic level and beyond.</p>



<p>The full study was published in the journal <em><a href="https://www.nature.com/articles/s41586-023-06011-w" target="_blank" rel="noreferrer noopener">Nature</a></em>.</p>



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



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Breakthrough: X-ray of a single atom captured for the first time

In a remarkable feat, a team of scientists has taken...

Hearing,Aid,And,Painful,Ear,Ache.,Hearing,Issue

<p>Recent research has challenged a longstanding theory about how humans pinpoint the origins of <a href="https://www.earth.com/news/noise-affects-sound-processing/" target="_blank" rel="noreferrer noopener">sounds</a> through spatial hearing -- a discovery with significant implications for the future of auditory technology. </p>



<p>Originally proposed in the 1940s, the established model suggested that humans locate sounds using a complex <a href="https://www.earth.com/news/alligators-spatial-hearing-mammals/" target="_blank" rel="noreferrer noopener">network of neurons</a> specifically tuned for spatial hearing. </p>



<p>This auditory spatial hearing model model has shaped the development of various auditory technologies, from hearing aids to smartphones, under the assumption that our auditory processing mirrors a highly specialized and intricate system.</p>



<p>However, recent findings from a team of researchers have turned this theory on its head. Their study demonstrates that, contrary to previous beliefs, our brains utilize a far less complex system for spatial hearing, similar to that of other mammals. </p>



<p>This revelation not only simplifies our understanding of human auditory processing but also paves the way for more efficient and adaptable hearing technologies.</p>



<h2 class="wp-block-heading" id="h-how-spatial-hearing-works">How spatial hearing works</h2>



<p>Also known as sound localization, spatial hearing is the ability of the auditory system to determine the location and direction of a sound source in three-dimensional space. </p>



<p>This ability is crucial for humans and many animals to navigate their environment, avoid dangers, and locate potential mates or prey. Key aspects of spatial hearing include:</p>



<ul>
<li><strong>Binaural cues</strong>: The brain uses differences in the timing and intensity of sound arriving at each ear to determine the location of the sound source. These cues are known as interaural time differences (ITDs) and interaural level differences (ILDs).</li>



<li><strong>Monaural cues</strong>: The shape of the outer ear (pinna) and the head itself affect the frequency spectrum of the sound reaching the eardrum. These spectral cues help in determining the elevation of the sound source and whether it is coming from the front or back.</li>



<li><strong>Head movements</strong>: Turning the head can help resolve ambiguities in sound localization, particularly in distinguishing between sounds coming from the front or back.</li>



<li><strong>The precedence effect</strong>: When a sound is followed by its echo, the auditory system gives precedence to the first-arriving sound, suppressing the perception of the echo. This helps in localizing sounds in reverberant environments.</li>



<li><strong>Auditory scene analysis</strong>: The brain can separate and group sounds from multiple sources based on their spatial locations, allowing us to focus on a particular sound source in a noisy environment (e.g., the "cocktail party effect").</li>
</ul>



<p>Spatial hearing is a complex process involving the interaction of various neural mechanisms in the brainstem, midbrain, and cortex.</p>



<h2 class="wp-block-heading" id="h-spatial-hearing-and-auditory-processing">Spatial hearing and auditory processing</h2>



<p>The research, conducted by a distinguished team from <a href="https://www.mq.edu.au/" target="_blank" rel="noreferrer noopener">Macquarie University</a>, utilized advanced hearing tests and brain imaging techniques to compare human auditory processing and spatial hearing with that of other mammals, including rhesus monkeys and gerbils. </p>



<p>What they discovered was surprisingly straightforward: rather than relying on a dense network of specialized neurons, both humans and other species employ a sparser and more energy-efficient neural network for spatial hearing.</p>



<p>"We like to think that our brains must be far more advanced than other animals in every way, but that is just hubris. We’ve been able to show that gerbils are like guinea pigs, guinea pigs are like rhesus monkeys, and rhesus monkeys are like humans in this regard," shares Distinguished Professor David McAlpine, the lead researcher.</p>



<h2 class="wp-block-heading" id="h-implications-for-hearing-technology-and-beyond">Implications for hearing technology and beyond</h2>



<p>This simpler approach to auditory processing is not only fundamental for spatial hearing but also crucial for distinguishing speech from <a href="https://www.earth.com/news/kids-blocking-background-noise-focus/" target="_blank" rel="noreferrer noopener">background noise</a>. This ability is vital in what's known as the 'cocktail party problem' -- the challenge of focusing on a single voice in a noisy environment.</p>



<p>Current technologies, including smart devices and <a href="https://www.earth.com/news/hearing-loss-linked-to-a-greater-risk-of-dementia/" target="_blank" rel="noreferrer noopener">hearing aids</a>, struggle with this issue, but the new findings suggest a shift towards simpler, more efficient neural models could lead to significant improvements.</p>



<p>Professor McAlpine suggests that the focus should move away from large language models, which are effective in predicting text but may be less suited for <a href="https://www.earth.com/news/covid-19-linked-to-hearing-loss-and-auditory-issues/" target="_blank" rel="noreferrer noopener">auditory</a> functions. "LLMs are brilliant at predicting the next word in a sentence, but they’re trying to do too much," Professor McAlpine remarks. </p>



<p>Instead, he advocates for a model that emulates the 'shallow brain' strategy used by humans and other animals, which involves picking out brief sound snippets and using them to identify the sound's location and possibly its source, without the need for processing the language.</p>



<h2 class="wp-block-heading" id="h-the-future-of-auditory-research">The future of auditory research</h2>



<p>The team is now set to explore further how minimal auditory information can still achieve maximum spatial hearing resolution. </p>



<p>Their findings not only enhance our understanding of human and <a href="https://www.earth.com/news/can-humans-hear-as-well-as-seals-underwater/" target="_blank" rel="noreferrer noopener">animal hearing</a> but also hold the potential to revolutionize how machines listen and interact with their environment. </p>



<p>By embracing the simplicity of our 'gerbil brain,' future technologies might be able to more effectively parse speech and sound in real-world settings, making them more intuitive and accessible for users worldwide.</p>



<p>This research marks a significant shift in our approach to designing auditory systems, both biological and mechanical, and could lead to a new generation of hearing devices that are both more natural in their function and more effective in their application.</p>



<p>The full study was published in the journal <em><a href="https://linkinghub.elsevier.com/retrieve/pii/S0960982224004743" target="_blank" rel="noreferrer noopener">Current Biology</a></em>.</p>



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Spatial hearing: How humans know where sounds come from

Recent research has challenged a longstanding theory about how humans...

<p></p>
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<p><br />
<span style="font-weight: 400;">Today’s </span><b>Video of the Day</b><span style="font-weight: 400;"> from the </span><a href="https://www.acs.org/"><span style="font-weight: 400;">American Chemical Society</span></a><span style="font-weight: 400;"> (ACS) explains why some of the water found in the hot springs of Yellowstone National Park can actually be deadly..</span></p>
<p><span style="font-weight: 400;">Hot springs are the result of geological activity within the Earth’s crust, and the water in Yellowstone often mixes with volcanic chemicals that make it acidic.</span></p>
<p><span style="font-weight: 400;">More dangerous than sulfuric acid, however, is the temperature of the water. Most hot springs are well over 150 degrees Fahrenheit, and some even reach close to 200 degrees.</span></p>
<p><span style="font-weight: 400;">This video is part of the ACS series </span><i><span style="font-weight: 400;">Reactions.</span></i></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: American Chemical Society</span></i></p>

What makes some of Yellowstone's hot springs deadly?