Today's Image of the Day from the European Space Agency features NGC 1792, a spiral galaxy located in the constellation Columba about 43 million light-years away from Earth.&nbsp;



This galaxy, discovered by British astronomer James Dunlop in 1826, is part of the larger NGC 1808 group of galaxies.&nbsp;



<h2 class="wp-block-heading" id="h-intimate-view-of-ngc-1792">Intimate view of NGC 1792</h2>



“An orange glow radiates from the center of NGC 1792, the heart of this stellar forge. Captured by the NASA/ESA Hubble Space Telescope, this intimate view of NGC 1792 gives us some insight into this galactic powerhouse,” noted <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>.



“The vast swathes of tell-tale blue seen throughout the galaxy indicate areas that are full of young, hot stars, and it is in the shades of orange, seen nearer the center, that the older, cooler stars reside.”



<h2 class="wp-block-heading" id="h-vigorous-star-formation-nbsp">Vigorous star formation&nbsp;</h2>



NGC 1792 is notable for its vigorous star formation, classifying it as a starburst galaxy. The high rate of star birth is thought to be triggered by gravitational interactions with neighboring galaxies, though the exact cause is still under study.



“Nestled in the constellation of Columba (The Dove), NGC 1792 is both a spiral galaxy, and a starburst galaxy,” said ESA. 



“Within starburst galaxies, stars are forming at comparatively exorbitant rates. The rate of star formation can be more than 10 times faster in a starburst galaxy than in the Milky Way.”



<h2 class="wp-block-heading" id="h-fierce-bursts-of-star-formation">Fierce bursts of star formation</h2>



ESA noted that when galaxies have a large reservoir of gas, like NGC 1792, these short-lived starburst phases can be sparked by galactic events such as mergers and tidal interactions.&nbsp;



“One might think that these starburst galaxies would easily consume all of their gas in a large forming event. However, supernova explosions and intense stellar winds produced in these powerful starbursts can inject energy into the gas and disperse it.”&nbsp;



“This halts the star formation before it can completely deplete the galaxy of all its fuel. Scientists are actively working to understand this complex interplay between the dynamics that drive and quench these fierce bursts of star formation.”



Due to its distance and brightness, NGC 1792 can be observed with medium-sized telescopes under favorable conditions.



<h2 class="wp-block-heading" id="h-the-evolution-of-galaxies">The evolution of galaxies </h2>



Galaxy evolution refers to the process by which galaxies form and change over time. It begins in the early universe, shortly after the <a href="https://www.earth.com/news/new-observations-disprove-big-bang-theory-universe-began-tired-light-theory/" target="_blank" rel="noreferrer noopener">Big Bang</a>, when small density fluctuations in the primordial gas led to the collapse of matter into the first galaxies.&nbsp;



<h3 class="wp-block-heading" id="h-galaxy-mergers">Galaxy mergers</h3>



Early galaxies were small and irregular, and were composed mostly of gas and dark matter. Over billions of years, galaxies grew larger by merging with one another and by accreting gas from the surrounding space.&nbsp;



These interactions often triggered bursts of star formation, and collisions between galaxies sometimes led to the creation of new, more massive galaxies.



<h3 class="wp-block-heading" id="h-structural-changes">Structural changes</h3>



As galaxies evolve, their morphology - shape and structure - can change. Early galaxies were often irregular or disk-shaped, but over time, many galaxies formed into the elliptical or spiral shapes we see today.&nbsp;



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



Star formation is a key driver of galaxy evolution, but it gradually slows down as galaxies age. 



The gas that fuels <a href="https://www.earth.com/news/black-hole-is-starving-its-host-galaxy-of-star-forming-fuel/" target="_blank" rel="noreferrer noopener">star formation</a> can be used up, or it can be heated and pushed out of galaxies by supernovae or black holes, reducing the galaxy's ability to form new stars.



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



The environment in which a galaxy resides also plays a role in its evolution. Galaxies in dense clusters are more likely to interact with their neighbors, which can alter their shape or trigger bursts of star formation.&nbsp;



In contrast, galaxies in more isolated regions of space evolve more slowly and without as many dramatic interactions.



<h3 class="wp-block-heading" id="h-dark-matter">Dark matter</h3>



Dark matter also plays a crucial role in galaxy evolution. It provides the gravitational framework that holds galaxies together and influences their interactions with one another.&nbsp;



Supermassive <a href="https://www.earth.com/search-results/?search=Galaxies%20merge&amp;start=0" target="_blank" rel="noreferrer noopener">black holes</a>, found at the centers of most large galaxies, can also affect their evolution by releasing energy that impacts star formation and the movement of gas within the galaxy.



Overall, galaxy evolution is a complex and ongoing process driven by interactions between stars, gas, <a href="https://www.earth.com/news/study-dark-matter-does-not-exist-and-the-universe-is-27-billion-years-old/" target="_blank" rel="noreferrer noopener">dark matter</a>, and black holes, and shaped by both internal processes and external influences.



Image Credit: ESA/Hubble &amp; NASA, J. Lee



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Starburst galaxy in the constellation Columba

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

Today's Image of the Day from the European Space Agency features a brilliant stellar nursery located about 163,000 light-years away.



According to ESA, the image is one of the most photogenic examples of the many stellar nurseries observed by the NASA/ESA Hubble Space Telescope during its 30-year lifetime. 



“The portrait features the giant nebula NGC 2014 and its neighbor NGC 2020 which together form part of a vast star-forming region in the Large Magellanic Cloud, a satellite galaxy of the Milky Way,” noted <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>.



<h2 class="wp-block-heading" id="h-what-is-a-stellar-nursery">What is a stellar nursery?</h2>



Stellar nurseries are regions in space where new stars are <a href="https://www.earth.com/news/baby-stars-release-sneezes-of-gas-and-dust-as-they-develop/" target="_blank" rel="noreferrer noopener">born</a> - often within vast clouds of gas and dust called molecular clouds.&nbsp;



These areas are fascinating because they are cradles of stellar evolution, where gravity causes clumps of gas to collapse, eventually forming protostars.&nbsp;



Over time, the protostars will heat up and start the nuclear fusion process that powers a star.



One of the most well-known stellar nurseries is the Orion Nebula, which is visible to the naked eye and located about 1,350 light-years from Earth.&nbsp;



<h2 class="wp-block-heading" id="h-dynamic-nature-of-a-stellar-nursery-nbsp">Dynamic nature of a stellar nursery&nbsp;</h2>



Within these nurseries, the balance between gravity and pressure determines the types of stars that form, from massive, luminous stars to smaller, cooler ones like our Sun.&nbsp;



The environment is incredibly dynamic, with powerful winds from young stars shaping the clouds and triggering the birth of even more stars.



These regions are often illuminated by the light from massive newborn stars - creating stunning, colorful displays. The light reveals the intricate structure of the dust and gas, sculpted by the energy of young stars.&nbsp;



<h2 class="wp-block-heading" id="h-significance-of-stellar-nurseries-nbsp">Significance of stellar nurseries&nbsp;</h2>



Stellar nurseries are essential for understanding the early stages of planetary formation, as protoplanetary disks (the material from which <a href="https://www.earth.com/news/planet-formation-new-insights-mechanics-physics/" target="_blank" rel="noreferrer noopener">planets form</a>) are often found around young stars in these regions.



Stellar nurseries play a crucial role in the ongoing evolution of <a href="https://www.earth.com/news/black-hole-is-starving-its-host-galaxy-of-star-forming-fuel/" target="_blank" rel="noreferrer noopener">galaxies</a>. They are responsible for the continuous birth of new stars that enrich the interstellar medium with heavier elements. This constant recycling of material is key to the development of future generations of stars and planets.&nbsp;



Furthermore, the study of these regions helps astronomers understand the fundamental processes that govern the life cycles of stars and the overall dynamics of the universe.



<h2 class="wp-block-heading" id="h-the-local-group">The Local Group</h2>



The Local Group is a collection of over 80 galaxies that includes the Milky Way, the Andromeda Galaxy, and the Triangulum Galaxy, along with numerous smaller dwarf galaxies. These galaxies are bound together by gravity and span a region roughly 10 million light-years across.&nbsp;



The <a href="https://www.earth.com/news/milky-ways-thin-disk-is-billions-of-years-older-than-we-thought/" target="_blank" rel="noreferrer noopener">Milky Way</a> and Andromeda are the dominant members, with their respective satellite galaxies orbiting them.&nbsp;



The Local Group is part of a larger structure known as the Virgo Supercluster, and its galaxies are moving toward the gravitational center of the Local Group, contributing to its dynamic nature.&nbsp;



<h2 class="wp-block-heading" id="h-large-magellanic-cloud">Large Magellanic Cloud</h2>



The Large Magellanic Cloud (LMC) is the fourth largest galaxy in the Local Group and can be seen with the naked eye from the Southern Hemisphere.&nbsp;



This irregular dwarf galaxy is home to the Tarantula Nebula, one of the most active star-forming regions in our cosmic neighborhood.&nbsp;



The Large Magellanic Cloud played a key role in astronomical history, particularly when the supernova SN 1987A was observed, providing valuable insights into stellar evolution.&nbsp;



The LMC's interaction with the Milky Way, along with its own companion, the Small Magellanic Cloud, is believed to influence its shape and star formation activity. Its proximity and unique properties make it a crucial object of study for understanding <a href="https://www.earth.com/news/massive-galactic-explosion-provides-clues-about-galaxy-evolution/" target="_blank" rel="noreferrer noopener">galaxy evolution</a>, star formation, and the dynamics of interacting galaxies.



Image Credit: NASA, ESA, and STScI



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Hubble captures a stunning stellar nursery

Today's Image of the Day from the European Space Agency features the barred spiral galaxy NGC 1559, located around 35 million light-years away in the southern constellation Reticulum. The image was captured by the James Webb Space Telescope.&nbsp;



"The data featured in this portrait make use of two of Webb’s instruments: the Mid-InfraRed Instrument (MIRI) and Near-InfraRed Camera (NIRCam)," noted <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>.



"Here MIRI captures the glow of interstellar dust grains, which trace out the interstellar medium, the fuel for future star formation. NIRCam shows the light from stars, even young stars hidden behind prodigious amounts of dust. NIRCam also captures emission from ionized nebulae around young stars."



<h2 class="wp-block-heading" id="h-webb-reveals-galaxies-in-new-light">Webb reveals galaxies in new light</h2>



According to ESA, the data was collected by the <a href="https://sites.google.com/view/phangs/home">PHANGS team</a> as part of a program in which Webb will observe 55 <a href="https://www.earth.com/news/james-webb-captures-galaxies-that-are-too-old-to-exist/">galaxies</a> that have also been mapped by the Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope, the Hubble Space Telescope, and more.&nbsp;



"By combining Webb’s unprecedented view of the dust and stars with data from these other facilities, the team aims to obtain a new, highly detailed view of how stars are born, live, and die in galaxies across the Universe."



<h2 class="wp-block-heading" id="h-ngc-1559-a-loner-in-space">NGC 1559: A loner in space</h2>



Although NGC 1559 appears to sit close to one of our nearest neighbors in the sky - the Large Magellanic Cloud (LMC) - this is just a trick of perspective, noted ESA.



While it is part of the Reticulum constellation, NGC 1559 is not part of the Local Group of galaxies but instead resides in a more distant region of space.



"In reality, NGC 1559 is physically nowhere near the LMC in space; in fact it truly is a loner, lacking the company of any nearby galaxies or membership of any galaxy cluster," said ESA.



<h2 class="wp-block-heading" id="h-star-formation-in-ngc-1559">Star formation in NGC 1559</h2>



NGC 1559 is notable for its active star formation and strong magnetic fields. It has also been the site of several <a href="https://www.earth.com/news/supernova-explosions-could-damage-distant-planets/" target="_blank" rel="noreferrer noopener">supernovae</a>, making it of particular interest to astronomers who study stellar evolution and the life cycle of stars.



The structure of NGC 1559 includes well-defined spiral arms that contain young, hot stars and regions of ionized gas, indicative of ongoing <a href="https://www.earth.com/news/black-hole-is-starving-its-host-galaxy-of-star-forming-fuel/" target="_blank" rel="noreferrer noopener">star formation</a>.



<h2 class="wp-block-heading" id="h-an-extragalactic-wonder">An extragalactic wonder</h2>



Despite being relatively small compared to larger galaxies like the Milky Way, NGC 1559 is an important object for understanding how barred spiral galaxies evolve and the processes that trigger supernovae.



The galaxy’s remote location and active nature make it a fascinating subject of study in the field of extragalactic astronomy. 



The isolation of NGC 1559 allows for a clearer view of its structure without much interference from neighboring galaxies.



<h2 class="wp-block-heading" id="h-barred-spiral-galaxies">Barred spiral galaxies</h2>



Barred spiral galaxies are a type of spiral galaxy characterized by a central bar-shaped structure composed of stars. This bar extends out from the core and connects to the galaxy's spiral arms, which swirl outward in a graceful pattern.



Scientists believe that the bar plays a crucial role in the evolution of the galaxy, funneling gas towards the core and potentially triggering star formation or feeding a central black hole. 



The <a href="https://www.earth.com/news/newly-discovered-stars-milky-way-are-old-as-universe/" target="_blank" rel="noreferrer noopener">Milky Way</a>, our own galaxy, is an example of a barred spiral. These galaxies are quite common in the universe, making up about two-thirds of all observed spiral galaxies.



The bar itself is thought to be a temporary feature, developing as the galaxy matures and possibly disappearing over time as the dynamics of the stars change. 



<h2 class="wp-block-heading" id="h-the-reticulum-constellation">The Reticulum constellation</h2>



Reticulum is a small, faint constellation in the southern sky. Its name means "the reticle" in Latin, which refers to the crosshairs in an eyepiece of a telescope.



The constellation was named in the 18th century by the French astronomer Nicolas Louis de Lacaille to honor the reticle he used in his scientific instruments. It is one of the 88 modern constellations recognized by the International Astronomical Union.



Image Credit: ESA/Webb, NASA &amp; CSA, A. Leroy, J. Lee and the PHANGS Team



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Spiral galaxy glows with young stars and interstellar dust

Today's Image of the Day from the European Space Agency features NGC 6744 - a large, barred spiral galaxy located approximately 30 million light-years away in the constellation Pavo.&nbsp;



The galaxy is often considered a close analog to the <a href="https://www.earth.com/news/uma3-u1-faintest-star-system-found-orbiting-milky-way-galaxy/" target="_blank" rel="noreferrer noopener">Milky Way</a> due to its similar structure and size, spanning about 175,000 light-years across.&nbsp;



<h2 class="wp-block-heading" id="h-euclid-space-mission-nbsp">Euclid space mission&nbsp;</h2>



The image was captured by the <a href="https://www.esa.int/Science_Exploration/Space_Science/Euclid" target="_blank" rel="noreferrer noopener">Euclid</a> space telescope. NGC 6744 stands out as a prime example of the galaxies currently forming the majority of stars in the nearby universe, making it an ideal subject for study with the Euclid mission.&nbsp;



Euclid’s extensive field-of-view allows it to capture the entire galaxy, showcasing not only its large-scale spiral structure but also revealing intricate details on smaller scales across various wavelengths. These details include feather-like dust lanes, known as “spurs,” emerging from the spiral arms.



<h2 class="wp-block-heading" id="h-star-formation-in-ngc-6744">Star formation in NGC 6744</h2>



Euclid's observations enable scientists to count individual stars within NGC 6744, trace the distribution of stars and dust throughout the galaxy, and map the dust associated with the gas that fuels the development of new stars.&nbsp;



<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 a key process in the growth of galaxies, making these studies crucial for understanding galaxy evolution.



Researchers are utilizing Euclid’s data to explore the relationship between dust, gas, and star formation. The data can also be used to map the distribution of different stellar populations and identify regions of active star formation.



Spiral arms play a significant role in star formation by compressing gas, yet the precise mechanisms behind this process are still unclear. 



The presence of “spurs” along NGC 6744’s spiral arms offers valuable insights into the dynamics of star formation within these structures.



<h2 class="wp-block-heading" id="h-discovering-new-dwarf-galaxies-nbsp">Discovering new dwarf galaxies&nbsp;</h2>



Additionally, Euclid's dataset will help scientists identify clusters of old stars (globular clusters) and discover new dwarf galaxies around NGC 6744. 



Remarkably, Euclid has already identified a new dwarf satellite galaxy of NGC 6744 - a surprising discovery given that the galaxy has been studied extensively.



With Euclid’s detailed observations, scientists are gaining a deeper understanding of the processes shaping galaxies, providing essential clues to the evolution and appearance of the <a href="https://www.earth.com/news/universes-expansion-rate-hubble-tension-puzzles-astronomers/" target="_blank" rel="noreferrer noopener">universe</a>.



<h2 class="wp-block-heading" id="h-more-about-ngc-6744">More about NGC 6744</h2>



NGC 6744's disk is rich in star-forming regions and contains numerous young, bright blue stars. The galaxy's nucleus is slightly elongated and has a bar structure, which influences the motion of the stars and gas within it.&nbsp;



The spiral arms of NGC 6744 are well-defined and extend outward, wrapping around the central bar. 



Additionally, NGC 6744 has a smaller companion galaxy, NGC 6744A, which is interacting with it, adding to the complexity and interest of this distant system.&nbsp;



<h2 class="wp-block-heading" id="h-types-of-spiral-galaxies">Types of spiral galaxies</h2>



<a href="https://www.earth.com/news/the-mesmerizing-beauty-of-spiral-galaxies/" target="_blank" rel="noreferrer noopener">Spiral galaxies</a> are one of the most common types of galaxies in the universe, characterized by their distinct, spiral-shaped structure.&nbsp;



The galaxies typically consist of a flat, rotating disk containing stars, gas, and dust, along with a central concentration of stars known as the bulge. This bulge is often surrounded by a halo of older stars.&nbsp;



The spiral arms, which extend from the central bulge, are regions of active star formation and are rich in young, hot stars, giving them a bright, bluish appearance.&nbsp;



These arms are also sites where interstellar gas and dust are concentrated, leading to the formation of new stars.&nbsp;



Spiral galaxies are classified into different types based on the tightness of their spirals and the size of their central bulge, with classifications ranging from tightly wound arms in Sa galaxies to more loosely wound arms in Sc galaxies. The <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</a>, our home galaxy, is a prime example of a spiral galaxy.



<h2 class="wp-block-heading" id="h-the-constellation-pavo">The constellation Pavo</h2>



Pavo, which means "peacock" in Latin, is a constellation in the southern sky. It was named by the Dutch astronomer Petrus Plancius in the late 16th century, based on observations made during the Dutch explorations of the southern hemisphere. 



Pavo is one of the 12 constellations created by Plancius from the records of explorers Pieter Dirkszoon Keyser and Frederick de Houtman. 



The constellation is known for its distinctive shape, resembling a peacock with a long, curved tail. It is not visible from most of the northern hemisphere, but it can be seen from the southern hemisphere, particularly during the winter months.



Pavo contains several interesting celestial objects, including the star Peacock, also known as Alpha Pavonis, which is the brightest star in the constellation. This star is a blue-white subgiant located about 179 light-years from Earth.



Image Credit: <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>/Euclid/Euclid Consortium/NASA&nbsp;



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Young stars illuminate a spiral galaxy in the constellation Pavo

Today's Image of the Day from NASA Earth Observatory features Lake Chad in central Africa. The photograph was taken by an astronaut aboard the International Space Station.



According to <a href="https://earthobservatory.nasa.gov/images/154407/lake-chads-water-wetlands-and-dunes" target="_blank" rel="noreferrer noopener">NASA</a>, Lake Chad once ranked among the largest natural lakes in the world. It was a critical resource for millions of people and animals, supporting agriculture and fishing across the region.&nbsp;



Lake Chad straddles the borders of Chad, Nigeria, Niger, and Cameroon. The shallow <a href="https://www.earth.com/news/lakes-are-warming-toward-the-point-of-no-return/" target="_blank" rel="noreferrer noopener">lake</a> is primarily fed by the Chari River, which brings water from the Central African Republic. 



The water levels are also influenced by seasonal rainfall. The rainfall patterns vary significantly across the basin but generally follow a wet-dry seasonal cycle.



<h2 class="wp-block-heading" id="h-environmental-decline-and-shrinkage-nbsp">Environmental decline and shrinkage&nbsp;</h2>



From the 1960s to the early 2000s, the lake lost more than 90 percent of its surface area. It transformed from a vast expanse of open water into a patchwork of wetlands, reed beds, and scattered pools.&nbsp;



This environmental decline has had severe consequences for local communities, leading to food and <a href="https://www.earth.com/news/global-water-security-relies-on-the-origins-of-rainfall/" target="_blank" rel="noreferrer noopener">water insecurity</a>, loss of livelihoods, and increasing competition over scarce resources.



“Ongoing droughts and the rising demand for fresh water have shrunk the lake to less than a tenth of the area it covered in the middle of the last century,” noted NASA.



“Although the lake has experienced dry and wet periods for thousands of years, there has been a significant decline in the amount of lake water available since the 1960s.”



<h2 class="wp-block-heading" id="h-conflict-culture-and-economy">Conflict, culture, and economy</h2>



Lake Chad is a geopolitical hotspot. The region has been affected by conflict, including the insurgency led by Boko Haram, which has displaced millions and further complicated efforts to manage and protect the lake’s fragile ecosystem.&nbsp;



Despite these challenges, regional governments and international organizations are working to restore and sustain the lake, including ambitious proposals to divert water from the Congo River basin.



Culturally and economically, Lake Chad remains vital. It is a hub for trade and social exchange among diverse ethnic groups and continues to provide fish and fertile land despite its reduced size.&nbsp;



The future of Lake Chad hinges on sustainable water management, <a href="https://www.earth.com/news/climate-extremes-alter-how-sunlight-travels-through-clear-lakes/" target="_blank" rel="noreferrer noopener">climate</a> resilience, and political cooperation across national boundaries.



<h2 class="wp-block-heading" id="h-evolution-of-lake-chad-nbsp">Evolution of Lake Chad&nbsp;</h2>



According to NASA, the evolution of Lake Chad has been documented by astronaut photography over the past 60 years.&nbsp;



“During the Apollo 7 mission in 1968, an astronaut acquired an oblique <a href="https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=AS07&amp;roll=8&amp;frame=1932" target="_blank" rel="noreferrer noopener">photograph</a> of the lake as one large body of water. In 1982, another <a href="https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=STS005&amp;roll=39&amp;frame=1022" target="_blank" rel="noreferrer noopener">photo</a> from the space shuttle mission STS-5 recorded receding water levels and encroaching sand dunes.”



“A <a href="https://eol.jsc.nasa.gov/SearchPhotos/photo.pl?mission=ISS042&amp;roll=E&amp;frame=244403" target="_blank" rel="noreferrer noopener">photo</a> taken in 2015 during space station Expedition 42 captured the lake’s remaining waters and wetlands in dark green, blue, and brown, contrasting with the sandy shades of the surrounding land.”&nbsp;



<h2 class="wp-block-heading" id="h-wildlife-of-lake-chad">Wildlife of Lake Chad</h2>



Lake Chad still supports wildlife, though species diversity and abundance have declined significantly due to ecosystem degradation



The lake and its surrounding wetlands are home to several species of fish, including tilapia, catfish, and Nile perch, which are important both ecologically and economically.&nbsp;



These fish support a major regional fishing industry, although overfishing and changes in water conditions have put pressure on fish populations.



Birds are another key component of the ecosystem. The lake serves as a crucial habitat and stopover point for <a href="https://www.earth.com/news/birds-may-be-using-quantum-physics-for-migration/" target="_blank" rel="noreferrer noopener">migratory birds</a> traveling along the African-Eurasian flyway. 



Species such as herons, storks, ducks, and geese can be found in the region, especially during the wet season when parts of the lake flood and create rich feeding grounds.



Mammals that depend on the surrounding floodplains and wetlands include hippos and various antelope species, yet their numbers have declined.&nbsp;



<h2 class="wp-block-heading" id="h-conservation-efforts-and-challenges">Conservation efforts and challenges</h2>



Reptiles like Nile crocodiles and turtles also inhabit the lake's waters and marshy areas. In the past, larger wildlife such as elephants and lions may have roamed the wider Lake Chad basin, but they are now mostly gone from the immediate lake area due to habitat loss and human activity.



Despite these challenges, Lake Chad remains an important, yet increasingly fragile, refuge for wildlife in a region where water and natural habitats are becoming more scarce.&nbsp;



Conservation efforts aim to balance the needs of people and <a href="https://www.earth.com/news/thousands-of-freshwater-species-are-threatened-with-extinction/" target="_blank" rel="noreferrer noopener">wildlife</a>, but the success of such efforts depends on managing the lake’s limited resources in the face of climate change, political instability, and population growth.



Image Credit: NASA Earth Observatory&nbsp;



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Lake Chad: A vanishing lifeline in Central Africa

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

Some bacteria have a chilling plan B. When nutrients vanish, they kill nearby cells and feast on the remains. A recent study shows this grisly move is anything but rare - it’s a survival trick hiding in plain sight.



The research was conducted by scientists from <a href="https://asuonline.asu.edu/?gclsrc=aw.ds&amp;&amp;utm_source=google&amp;utm_medium=cpc&amp;utm_content=BR_Main_ASU_Non&amp;utm_campaign=22-Nat_Acq-Hi_BR_Main_Non_OS&amp;utm_ecd22=22&amp;utm_term=arizona+state+university&amp;gad_source=1&amp;gad_campaignid=10205493793&amp;gclid=Cj0KCQjwmK_CBhCEARIsAMKwcD4F16NXdbbw5yWnLQpde7MCm6ecUTHOSmTy_9hkkLNe1vAW_g2rwoEaAiAkEALw_wcB" target="_blank" rel="noreferrer noopener">Arizona State University</a>, ETH Zurich, and the Swiss Federal Institute of Aquatic Science and Technology (Eawag).



The experts discovered that hungry bacteria switch on a tiny weapon called the <a href="https://www.earth.com/news/bacteria-pseudomonas-build-tiny-nano-spearguns-to-fight-back-against-attack/" target="_blank" rel="noreferrer noopener">Type VI Secretion System</a> (T6SS) to stay alive.



<h2 class="wp-block-heading" id="h-some-bacteria-eat-their-neighbors">Some bacteria eat their neighbors</h2>



Dr. Glen D’Souza, a co-author of the study, does not sugar-coat the finding. “The punchline is: when things get tough, you eat your neighbors,” he said.



“We’ve known bacteria kill each other, that’s textbook. But what we’re seeing is that it's not just important that the bacteria have weapons to kill, but they are controlling when they use those weapons specifically for situations to eat others where they can't grow themselves.” 



<h2 class="wp-block-heading" id="h-hungry-bacteria-turn-predatory">Hungry bacteria turn predatory</h2>



The T6SS is a needle-like harpoon. A cell fires it into a neighbor and injects lethal toxins. Earlier studies suggested the device cleared space for growth. 



The new data show a darker aim. The killer waits until food is gone, then strikes so it can feed on leaking nutrients.



Ferran Garcia-Pichel puts it in human terms. “Most bacteria quietly gather nutrients from their surroundings, but a few are known to be specialist hunters, killing and consuming other organisms or cells,” he says. 



“This study and Dr. D’Souza’s team reveal that even so-called harmless bacteria can become killers under stress. When resources run low, even seemingly harmless bacteria can flip, a microbial Jekyll and Hyde. Their beauty, it turns out, is only skin-deep.” 



<h2 class="wp-block-heading" id="h-a-silent-arms-race-among-microbes">A silent arms race among microbes</h2>



In the microbial world, <a href="https://www.earth.com/news/city-microbes-are-finding-surprising-new-ways-to-survive/" target="_blank" rel="noreferrer noopener">survival</a> depends not only on speed or size, but also on strategy. And weapons like the T6SS are just one part of a much larger arms race happening invisibly all around us. 



Many bacteria live in dense, competitive communities - inside <a href="https://www.earth.com/news/how-soil-bacteria-contribute-to-atmospheric-co2/" target="_blank" rel="noreferrer noopener">soil</a>, seawater, or even your digestive tract - where the line between coexistence and conflict is razor-thin.



These microscopic organisms are constantly scanning their surroundings, sizing up friend or foe. Some form alliances. Others, like those with T6SS, keep quiet until resources run low - then strike with precision. 



What makes this tool unique is that it’s not used randomly. It’s a calculated move, triggered only under stress. This level of control suggests bacteria are not mindless killers, but adaptive survivors with a strong sense of timing. 



Bacteria don’t just fight for territory - they wait until the cost of not attacking is greater than the risk of war. In that way, bacterial life mirrors the same resource-driven dynamics seen in larger ecosystems, just on a much smaller scale.



By decoding how and when <a href="https://www.earth.com/news/bacteria-pass-down-their-memories-to-fight-viruses/" target="_blank" rel="noreferrer noopener">bacteria fight</a>, scientists are beginning to map the invisible power structures that govern the microbial world.



<h2 class="wp-block-heading" id="h-hungry-bacteria-kill-to-eat">Hungry bacteria kill to eat</h2>



The team used time-lapse imaging, genetic switches, and chemical labels. They watched the tiny hunters pierce victims, wait, and then grow on the spill. 



When the scientists disabled the harpoon in some strains, those mutants starved. The untouched strains thrived.



“This isn’t just happening in the lab,” noted Dr. D’Souza. “It’s present in many different environments and it's operational and happening in nature from the oceans to the <a href="https://www.earth.com/news/human-gut-bacteria-feed-on-complex-plant-sugars/" target="_blank" rel="noreferrer noopener">human gut</a>.”



Astrid Stubbusch saw the attacks frame by frame. She said that watching these cells in action really drives home how resourceful bacteria can be.



“By slowly releasing nutrients from their neighbors, they maximize their nutrient harvesting when every molecule counts - revealing a new link in the microbial food web that we’ve not appreciated before," said Stubbusch.



<h2 class="wp-block-heading" id="h-tiny-killers-big-impact">Tiny killers, big impact</h2>



Understanding these weapons could shape better probiotics that patrol the gut. The same tool might inspire new antibiotics that shove drugs straight into harmful bugs. 



On a global scale, bacterial skirmishes may even nudge the carbon cycle by changing which microbes break down algae in the sea.



Bacteria are not just passive recyclers. When the cupboard is bare, they turn into hunters. In the microscopic world, survival sometimes means eating the neighbor next door.



The full study was published in the journal <a href="https://www.science.org/doi/10.1126/science.adr8286" target="_blank" rel="noreferrer noopener">Science</a>.



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When bacteria get hungry, they turn on each other

Some bacteria have a chilling plan B. When nutrients vanish,...

Somewhere deep inside a salt cave in Hallstatt, Austria, a small crystal disk stores the entire human genome. Called a "5D memory crystal," it may hold the key to humanity’s future, while also offering a second chance for species currently on the brink of extinction. 



This silica disc, smaller than a poker chip, carries every one of the three billion letters in human DNA, locked away in a format designed to shrug off fire, ice, radiation, and the slow grind of time itself. 



Its makers want it to outlast oceans, continents, and even the universe itself, ready to give future explorers a snapshot of who we were.



This bold initiative is made possible by a technological leap in <a href="https://www.earth.com/news/cells-called-astrocytes-help-human-brains-store-massive-amounts-of-information/" target="_blank" rel="noreferrer noopener">data preservation</a>. Hard drives corrode, magnetic tape demagnetizes, and cloud servers rely on electricity that must never blink. 



A storage method capable of surviving billions of years pushes the conversation from quarterly backups to civilizational memory. If humanity ever blinks out, this disc could become the spark that lights the way back.



<h2 class="wp-block-heading" id="h-tiny-disk-will-protect-the-human-genome">Tiny disk will protect the human genome</h2>



A single five-dimensional memory crystal holds up to 360 terabytes - enough room for roughly seventy-five million songs. 



The medium is fused quartz, one of Earth’s toughest glasses, famous for shrugging off chemical attack and temperature swings. 



Tests show the crystal keeps its data after heating to 1,832 °F, freezing to the cold of liquid nitrogen, or absorbing cosmic rays that would fry silicon chips. 



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2025/06/5D-memory-crystal_human-genome-storage_eternity_credit-USouthampton_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2025/06/5D-memory-crystal_human-genome-storage_eternity_credit-USouthampton_1s.webp" alt="The 5D memory crystal was developed by the University of Southampton's Optoelectronics Research Center (ORC)." class="wp-image-1973755"/></a><figcaption class="wp-element-caption">The 5D memory crystal was developed by the University of Southampton's Optoelectronics Research Center (ORC). Click image to enlarge.</figcaption></figure>



Engineers have even pressed it with 10 tons of force per square centimeter without leaving a scar. No wonder Guinness World Records called it the most durable data storage material back in 2014.



<a href="https://www.earth.com/news/goodbye-electrons-future-computers-may-be-powered-by-magnons/" target="_blank" rel="noreferrer noopener">Durability matters</a> because information usually vanishes long before the heat death of the universe. Everyday flash memory may lose bits after a decade on the shelf. 



Film yellows, parchment crumbles, and even punched tapes break their sprocket holes. In contrast, the five-dimensional approach literally engraves data inside the glass. 



Tiny patterns, each only 20 nanometers wide - about one six-thousandth the width of a human hair - change how light passes through. 



Those subtle tweaks can later be read with a microscope and <a href="https://www.earth.com/news/quantum-secrets-of-water-molecules-discovered-in-the-lab-through-spectroscopy/" target="_blank" rel="noreferrer noopener">polarized beam</a>. Because the marks hide beneath the surface, scratches, oxidation, and mold barely touch them.



<h2 class="wp-block-heading" id="h-writing-in-five-dimensions">Writing in five dimensions</h2>



Writing the code is a dance of ultrafast laser pulses. Each burst lasts only a few femtoseconds - a <a href="https://www.earth.com/news/watching-electrons-move-1-quintillionth-of-second-attoseconds-attomicroscopy/" target="_blank" rel="noreferrer noopener">femtosecond</a> is one quadrillionth of a second - yet it leaves a permanent imprint. 



The pulses create tiny voids whose orientation, size, and position encode bits in two optical axes plus three spatial coordinates. That is why technologists call it five-dimensional data. 



Unlike ink, magnetic domains, or pits on a compact disc, these features stack in three-dimensional layers, using the entire volume of the glass instead of its skin.



Because the process needs pinpoint accuracy, the laser setup sits on vibration-damped tables in clean rooms. A single misaligned pulse could blur the pattern, so motion stages move in nanometer steps while real-time optics check focus. 



It can take hours to write a complex file, yet the payoff is permanence. 



Once sealed, the disc rests at room temperature - no batteries and no hard drive platters spinning at 7,200 rpm. In archival terms, that is invincibility on a budget.



<h2 class="wp-block-heading" id="h-etching-the-human-genome-onto-a-disk">Etching the human genome onto a disk</h2>



The idea is more than laboratory tinkering. After perfecting the technique, researchers at the Optoelectronics Research Center of the <a href="https://www.southampton.ac.uk/" target="_blank" rel="noreferrer noopener">University of Southampton</a> decided to pack humanity’s most precious dataset into a single disc. 



The effort is headed by physicist <a href="https://www.southampton.ac.uk/people/5wzgcb/professor-peter-kazansky" target="_blank" rel="noreferrer noopener">Peter Kazansky</a>, whose group has spent years refining femtosecond-laser writing. They etched the entire human genome - about 3.2 billion base pairs - into the crystal, sequencing each letter 150 times to catch errors, with help from <a href="https://www.linkedin.com/company/helixworks" target="_blank" rel="noreferrer noopener">Helixwork Technologies</a>.



“We know from the work of others that genetic material of simple organisms can be synthesized and used in an existing cell to create a viable living specimen in a lab,” Professor Kazansky explains.



“The 5D memory crystal opens up possibilities for other researchers to build an everlasting repository of genomic information from which complex <a href="https://www.earth.com/news/ai-deciphers-plant-dna-a-breakthrough-that-will-transform-agriculture/" target="_blank" rel="noreferrer noopener">organisms like plants</a> and animals might be restored should science in the future allow.” 



Those ambitions reach beyond curiosity; they sketch a plan for a biological seed bank that could survive long after today’s seed vaults crumble.



<h2 class="wp-block-heading" id="h-storing-the-disk-that-holds-the-code">Storing the disk that holds the code</h2>



The finished disc now sits in the <a href="https://www.memory-of-mankind.com/" target="_blank" rel="noreferrer noopener">Memory of Mankind archive</a>, a cavern carved into Austrian salt deposits. Above its dense planes of data lies a visual key. 



The engravings show hydrogen, carbon, nitrogen, and oxygen; the familiar A, C, G, and T bases; a double helix; and finally a chromosome sliding into a cell. 



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2025/06/5D-memory-crystal_memory-of-humankind-cave_credit-USouthampton_1m.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2025/06/5D-memory-crystal_memory-of-humankind-cave_credit-USouthampton_1s.webp" alt="Memory of Mankind archive in Hallstatt, Austria. Credit: University of Southampton" class="wp-image-1973757"/></a><figcaption class="wp-element-caption">Memory of Mankind archive in Hallstatt, Austria. Click image to enlarge. Credit: University of Southampton</figcaption></figure>



The design assumes the finder may have no cultural reference points, only the universal language of chemistry and geometry.



<h2 class="wp-block-heading" id="h-bringing-humans-back-from-extinction">Bringing humans back from extinction</h2>



It's one thing to find the disk, but it's another thing entirely to actually do something with it.



An alien civilization that uncovers this 5D crystal disk would hold a vast instruction set explaining how to build a human, but it will be written in an unfamiliar language. 



Decoding the sequence demands mastery of <a href="https://www.earth.com/news/universal-rule-of-biology-sai-proposed-to-explain-aging-and-how-to-control-it/" target="_blank" rel="noreferrer noopener">molecular biology</a>, cellular development, and <a href="https://www.earth.com/news/random-dna-mutations-shape-biological-aging/" target="_blank" rel="noreferrer noopener">epigenetics</a>, because sequence data alone cannot produce a person. 



Researchers must first synthesize flawless DNA strands, assemble them into forty-six chromosomes, position them inside a nucleus, and place that nucleus in an enucleated human egg. 



Yet the embryo’s journey <a href="https://www.earth.com/news/how-life-begins-egg-sperm-and-a-covert-team-of-proteins/" target="_blank" rel="noreferrer noopener">from zygote to adult</a> depends on more than genetic code. 



Chemical gradients, mechanical forces, and maternal hormones orchestrate the timed expression of genes that sculpt tissues and organs. 



Without that context, the visitors must reconstruct life’s regulatory software, mapping how <a href="https://www.earth.com/news/rna-breakthrough-sheds-light-on-the-beginning-of-life/" target="_blank" rel="noreferrer noopener">RNA and proteins fold</a>, interact, and direct cognition and behavior. 



This incredible storage disk reveals our ingredients, but not the recipe for animation. Transforming code into consciousness would resemble crafting a violin solely from sheet music.



<h2 class="wp-block-heading" id="h-beyond-humanity-a-genetic-ark">Beyond humanity: a genetic ark</h2>



The same technology could house the genomes of mountain gorillas, Tasmanian devils, or giant sequoias - organisms edging uncomfortably close to oblivion. 



A single shoebox of crystals would dwarf the capacity of today’s cold-storage DNA banks while avoiding their dependence on liquid nitrogen. 



In a nod to <a href="https://science.nasa.gov/resource/pioneer-plaque/" target="_blank" rel="noreferrer noopener">NASA’s Pioneer plaques</a>, Kazansky’s team etched a silhouette onto the disc’s surface as a greeting to whoever encounters it. 



“The visual key inscribed on the crystal gives the finder knowledge of what data is stored inside and how it could be used,” says Professor Kazansky. 



“We don't know if memory crystal technology will ever follow these plaques in distance traveled, but each disc can be expected, with a high degree of confidence, to exceed their survival time."



Five-dimensional crystals will not solve every backup headache, but they make one promise: once data goes in, it stays. 



That promise turns a fragile string of nucleotides into a message that can cross oceans of time, waiting for minds clever enough to read it - and perhaps brave enough to breathe life into it.



This extraordinary achievement was made possible through a collaboration with <a href="https://www.helix.works/" target="_blank" rel="noreferrer noopener">Helixworks Technologies</a>.



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The entire human genome is stored on this disk - could aliens build a human with this data?

Somewhere deep inside a salt cave in Hallstatt, Austria, a...

Mammoth Cave in Kentucky stretches for more than 420 miles (675 kilometers) below the surface of the ground and is often described as the world’s largest cave system. Recent explorations there uncovered two new fossil sharks that once roamed shallow coastal waters more than 325 million years ago.



Ancient shark specialist John-Paul (JP) Hodnett of the Maryland-National Capital Parks and Planning Commission (<a href="https://www.mncppc.org/" target="_blank" rel="noreferrer noopener">MNCPPC</a>) worked with the <a href="https://www.nps.gov/subjects/fossils/index.htm">National Park Service Paleontology Program</a> to identify the fossils. 



These finds have everyone buzzing because they offer a glimpse into marine habitats that thrived when parts of what is now eastern North America were covered by a warm sea.



<h2 class="wp-block-heading" id="h-prehistoric-shark-fossil-puzzle">Prehistoric shark fossil puzzle</h2>



The newly documented sharks are Troglocladodus trimblei and Glikmanius careforum, and they are from a group known as <a href="https://www.uky.edu/KGS/fossils/fossil-month-cten.php">ctenacanth</a> sharks. 



They both measured about 10–12 feet (3–3.6 meters) long, which is similar in size to an oceanic whitetip shark.



The shark fossils were collected from various limestone formations, which were deposited during the Middle to Late <a href="https://www.nps.gov/articles/000/mississippian-period.htm">Mississippian Period</a>. 



The bigger picture is that these habitats were once submerged under shallow seas and supported a wide range of fish life. Researchers have now identified more than 70 ancient fish species in the cave system.



A partial set of jaws belonging to a young <a href="https://shark-references.com/species/view/Glikmanius-careforum">Glikmanius careforum</a> revealed fresh details about cartilage, which rarely fossilizes well. 



Cartilaginous remains of sharks are often fragile and easily destroyed by erosion, so finding them preserved in a protected space is especially rewarding.



Experts note that this newly identified material adds depth to ongoing discussions of how shark groups diversified while the supercontinent <a href="https://www.usgs.gov/faqs/what-was-pangea">Pangea</a> was taking shape.



<h2 class="wp-block-heading" id="h-collaborations-and-fieldwork">Collaborations and fieldwork</h2>



“Every new discovery at Mammoth Cave is possible due to collaborations,” said park superintendent <a href="https://www.nps.gov/maca/learn/management/index.htm">Barclay Trimble</a> of Mammoth Cave National Park. 



Researchers and volunteers have explored hidden passages, river channels, and even narrow crawlways in search of key fossils.



Members of the <a href="https://www.cave-research.org/" target="_blank" rel="noreferrer noopener">Cave Research Foundation</a> also took part in these efforts. The name Glikmanius careforum was chosen to honor that organization’s valuable support in the field.



The partial cartilage from this genus points to a short head with a strong bite, possibly used to feed on smaller fish and <a href="https://www.geo.mtu.edu/KeweenawGeoheritage/HoughtonEC/Orthocones.html">orthocones</a>, which are squid-like creatures with elongated shells.



<h2 class="wp-block-heading" id="h-fossils-help-trace-evolutionary-change">Fossils help trace evolutionary change </h2>



Troglocladodus trimblei stands out for its branching tooth design that helped it secure prey in the Mississippian seas. 



This prehistoric hunter probably shared a coastal environment with G. careforum, in waters that covered modern-day Kentucky and Alabama.



Researchers say these sharks likely thrived in nearshore habitats that teemed with bony fish, shelled organisms, and other <a href="https://www.earth.com/news/cocaine-sharks-brazilian-waters-sharpnose-sharks-rhizoprionodon-lalandii-ocean-pollution/">marine creatures</a>.



Tracing these fossils across multiple rock layers provides insights into how the environment changed over time. 



Coastal waters rose and fell as landmasses drifted toward each other, gradually merging into a single continent. 



These broader patterns helped shape the distribution and evolutionary paths of ancient sharks like T. trimblei and G. careforum.



<h2 class="wp-block-heading" id="h-how-to-preserve-shark-fossils">How to preserve shark fossils</h2>



Field teams spent long hours underground carefully mapping and collecting small fragments of teeth. A single <a href="https://www.npca.org/articles/7703-the-unveiling-of-mammoth-cave-s-history">tooth</a> from T. trimblei sparked initial interest when Superintendent Trimble first discovered it on a 2019 trip. 



Seasoned cavers and geologists coordinated to ensure safe retrieval of each piece, knowing that one misstep could damage the delicate remains.



<figure class="wp-block-image aligncenter size-full"><a href="https://www.earth.com/wp-content/uploads/2025/06/ctenacanth-sharks_cave-discovery_325-million-years-ago_1big.jpg" target="_blank" rel="noreferrer noopener"><img src="https://www.earth.com/wp-content/uploads/2025/06/ctenacanth-sharks_cave-discovery_325-million-years-ago_1s.webp" alt="A reconstruction of the new Middle to Late Mississippian ctenacanth sharks from Mammoth Cave National Park and northern Alabama. Glikmanius careforum is seen swimming in the foreground with two Troglocladodus trimblei swimming above. Artwork by Benji Paynose" class="wp-image-1973763"/></a><figcaption class="wp-element-caption">A reconstruction of the new Middle to Late Mississippian ctenacanth sharks from Mammoth Cave National Park and northern Alabama. Glikmanius careforum is seen swimming in the foreground with two Troglocladodus trimblei swimming above. Click image to enlarge. Artwork by Benji Paynose</figcaption></figure>



Research at Mammoth Cave has led to conversations about how best to preserve fragile fossils within difficult-to-access passages. Experts say stable cave temperatures help keep these discoveries in good condition. 



Park managers have also integrated these new data into guidelines for future research so that more clues to marine life from 325 million years ago may be found.



<h2 class="wp-block-heading" id="h-why-these-shark-fossils-matter">Why these shark fossils matter</h2>



Scientists use these finds to compare local fossil collections with specimens from similar periods in other parts of the world. 



Documenting body sizes, tooth arrangements, and skeletal details helps researchers build a clearer timeline of shark <a href="https://www.earth.com/news/shark-skeletons-could-lead-to-technological-innovations/">evolution</a>.



These comprehensive studies uncover shifts in fish diversity that occurred as oceans changed and landmasses joined together. 



Experts also link fossil data with knowledge from bony fish records, coral structures, and other sea life. This combined approach paints a full picture of ancient marine habitats and shows how some species adapted while others vanished. 



The two new fossil sharks at Mammoth Cave highlight that even well-known geologic areas can hold <a href="https://www.earth.com/news/octopus-caught-riding-on-the-back-of-the-worlds-fastest-shark-in-the-open-ocean/">surprises</a> for many years.



<h2 class="wp-block-heading" id="h-future-cave-explorations">Future cave explorations</h2>



Mammoth Cave continues to yield glimpses into a vanished coastline that spanned what is now Kentucky, Europe, and northern Africa. 



T. trimblei and G. careforum are just two recent additions to an ever-expanding fossil catalog, reminding everyone that exploration still brings answers and new questions.



In many ways, these ancient sharks highlight how puzzle pieces of geologic history keep fitting together. Field teams are now eager to see what lies in deeper chambers or behind the narrow channels.



The next phase of study may involve more advanced imaging and careful excavation in lesser-known passages, guided by new mapping techniques. 



Findings like these spur a broader appreciation for the cave system’s scientific value, well beyond its length or visual features.



The study is published in the <a href="https://www.researchgate.net/publication/377873693_NEW_CTENACANTH_SHARKS_CHONDRICHTHYES_ELASMOBRANCHII_CTENACANTHIFORMES_FROM_THE_MIDDLE_TO_LATE_MISSISSIPPIAN_OF_KENTUCKY_AND_ALABAMA">Journal of Vertebrate Paleontology</a>.



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Two prehistoric sea monsters found in the world's largest cave after 325 million years

Mammoth Cave in Kentucky stretches for more than 420 miles...

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