Today's Image of the Day from NASA Earth Observatory features the Ruki River in the Democratic Republic of the Congo (DRC). It is a tributary of the Congo River, one of the largest rivers in the world by discharge and depth.&nbsp;



The Ruki River, previously known as the Busira, merges with the Momboyo River near the town of Basankusu to become the Lulonga River, which eventually flows into the Congo River at the town of Lisala.



<h2 class="wp-block-heading" id="h-dark-waters-of-the-ruki-river">Dark waters of the Ruki River</h2>



"If the appearance of the muddy Amazon River evokes a coffee cut with cream, the Ruki River, coursing gently through the Congo Basin, is like a dark tea," said <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA</a>.



"On its slow path through mostly untouched lowland rainforest in the Democratic Republic of Congo (DRC), the water leaches organic material from vegetation, prompting some researchers to think it is one of the darkest blackwater rivers on Earth."



According to NASA, scientists are finding that the dissolved material in this distinctive water offers clues about the carbon cycle of tropical forests.



<h2 class="wp-block-heading" id="h-organic-compounds-in-the-ruki-river">Organic compounds in the Ruki River</h2>



In a recent study, researchers measured the chemical <a href="https://www.earth.com/news/warmer-rivers-keep-antimicrobial-resistant-genes-at-bay/" target="_blank" rel="noreferrer noopener">composition</a> and flow of the Ruki for the first time.&nbsp;



"The study reported that, as the water color suggests, the Ruki is rich in dissolved organic carbon compounds," said NASA.



"It contains four times as much organic carbon as the Congo River and 1.5 times as much as the Rio Negro, the world’s largest blackwater river and a major tributary of the Amazon."



Due to this heavy carbon load, the researchers concluded that tropical forests like those around the Ruki might not accumulate quite as much carbon as we once thought.



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



The river is vital for the livelihoods of local communities. <a href="https://www.earth.com/news/fishing-communities-cooperate-to-survive-climate-change/" target="_blank" rel="noreferrer noopener">Fishing</a> is a crucial activity, with many people depending on it for sustenance and income. The river also supports agriculture along its banks, where communities grow crops.



In many parts of the DRC, <a href="https://www.earth.com/news/rivers-are-warming-up-and-losing-oxygen-faster-than-oceans/" target="_blank" rel="noreferrer noopener">rivers</a> like the Ruki are crucial transportation corridors due to the challenging and often nonexistent road infrastructure. 



The river enables the movement of people and goods, facilitating trade and access to markets, health care, and education.



<h2 class="wp-block-heading" id="h-wildlife-of-the-ruki-river">Wildlife of the Ruki River </h2>



The region around the Ruki River is home to diverse wildlife. It is part of the Congo Basin, the second-largest tropical rainforest area in the world, which is a critical habitat for endangered species.



Among the most notable species are elephants and <a href="https://www.earth.com/news/study-mean-chimpanzees-fare-better-in-life-than-nice-ones/" target="_blank" rel="noreferrer noopener">chimpanzees</a>, whose populations thrive in the surrounding forests. Other primates such as bonobos also live in this region, making it a critical area for primate conservation.



The river itself is home to various species of fish that are crucial to local livelihoods. Hippopotamuses and crocodiles are often found in the water.



Birds like kingfishers, herons, and egrets frequent the riverbanks - making it a haven for birdwatchers.



The Ruki River also supports several species of reptiles and amphibians - some of which are unique to the region.



<h2 class="wp-block-heading" id="h-managing-the-river-s-resources">Managing the river's resources </h2>



The region faces several challenges, including <a href="https://www.earth.com/news/global-deforestation-directly-linked-to-atmospheric-mercury-emissions/" target="_blank" rel="noreferrer noopener">deforestation</a>, overfishing, and environmental degradation, which threaten its ecological balance and the livelihoods of people who depend on it. 



Efforts to manage and conserve the river's resources are vital for sustainable development.



Understanding and protecting the Ruki River and its surroundings are crucial for the DRC's environmental sustainability, economic development, and the well-being of its communities.



<h2 class="wp-block-heading" id="h-landscapes-of-the-drc">Landscapes of the DRC</h2>



The Democratic Republic of Congo (DRC) boasts some of the most diverse and breathtaking landscapes in Africa, reflecting its vast size and ecological richness. Dominated by the Congo Basin, the country is a haven for biodiversity.



Beyond its rainforests, the DRC's landscapes shift dramatically. In the east, the terrain rises into rugged mountains, including the Virunga and Rwenzori ranges, where snow-capped peaks like Mount Stanley pierce the sky. 



This region is also marked by active volcanoes such as Mount Nyiragongo, which harbors one of the world’s largest lava lakes, creating a dramatic and otherworldly spectacle.



To the south and west, the country transitions to expansive savannas with rolling grasslands and scattered trees. These areas contrast sharply with the lushness of the forests, providing vital habitats for species like lions and antelope. 



Rivers like the Ruki are a dominant feature, with the mighty Congo River coursing through the heart of the country. Its tributaries shape the lives of millions.



The image was captured by the OLI (Operational Land Imager) on Landsat 8.



Image Credit: NASA Earth Observatory&nbsp;



-----



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



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



-----

Ruki River in the Democratic Republic of the Congo

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

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



-----



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



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



-----

Hubble captures a stunning stellar nursery

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

Today's Image of the Day from the European Space Agency features the Southern Ring Nebula, also known as NGC 3132.



The nebula is located about 2,000 light-years away from Earth in the constellation Vela. This remarkably detailed image was created using data from Webb’s Near-Infrared Camera (NIRCam).



The Southern Ring Nebula is one of the more famous examples of planetary nebulae. It is often studied for its beauty and valuable insights into the end stages of stellar evolution.



<h2 class="wp-block-heading" id="h-stars-power-the-southern-ring-nebula-nbsp">Stars power the Southern Ring Nebula&nbsp;</h2>



The <a href="https://www.earth.com/news/dragons-egg-nebula-is-a-truly-stunning-sight-to-behold/" target="_blank" rel="noreferrer noopener">nebula</a> is powered by two central stars in a binary system. The brighter star is actually a less massive companion. The fainter, dimmer star is the dying, hot central star that has shed its outer layers to form the nebula. 



The dimmer star is a white dwarf and is responsible for the ionization of the gas in the nebula, causing it to glow.



“The bright star at the center of NGC 3132, while prominent when viewed by NASA’s Webb Telescope in near-infrared light, plays a supporting role in sculpting the surrounding nebula," noted <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>.



"A second star, barely visible at lower left along one of the bright star’s diffraction spikes, is the nebula’s source. It has ejected at least eight layers of gas and dust over thousands of years.” 



“But the bright central star visible here has helped ‘stir’ the pot, changing the shape of this planetary nebula’s highly intricate rings by creating turbulence." 



ESA explained that the pair of stars are locked in a tight orbit, which leads the dimmer star to spray ejected material in a range of directions as they orbit one another, resulting in these jagged rings.



<h2 class="wp-block-heading" id="h-key-characteristics-of-the-southern-ring-nebula-nbsp">Key characteristics of the Southern Ring Nebula&nbsp;</h2>



The Southern Ring Nebula displays a complex structure with multiple layers of gas and dust. 



The outer shells of the nebula consist of hydrogen and other elements that were ejected from the dying star in previous stages of its <a href="https://www.earth.com/news/young-stellar-objects-observing-the-early-lives-of-stars/" target="_blank" rel="noreferrer noopener">evolution</a>. These layers are illuminated by ultraviolet radiation from the central white dwarf.



<h3 class="wp-block-heading" id="h-coloration">Coloration</h3>



The colors seen in the Southern Ring Nebula come from the different gases present. For example, hydrogen emits red light, while oxygen emits blue-green light. 



These colors help astronomers study the composition and dynamics of the nebula.



<h3 class="wp-block-heading" id="h-size-and-shape">Size and shape</h3>



The nebula spans about half a light-year in diameter. Its intricate, symmetrical structure provides valuable insights into the late stages of <a href="https://www.earth.com/news/star-collapse-black-hole-instead-of-supernova-vanish-from-sky/" target="_blank" rel="noreferrer noopener">stellar evolution</a>, especially the processes involved in the shedding of outer layers by dying stars.



<h2 class="wp-block-heading" id="h-spotlights-from-the-bright-star">Spotlights from the bright star</h2>



ESA noted that hundreds of straight, brightly-lit lines pierce through the rings of gas and dust. “These ‘spotlights’ emanate from the bright star and stream through holes in the nebula like sunlight through gaps in a cloud."



“But not all of the starlight can escape. The density of the central region, set off in teal, is reflected by how transparent or opaque it is. Areas that are a deeper teal indicate that the gas and dust are denser - and light is unable to break free.”



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



According to ESA, this is not only a crisp image of a planetary nebula - it also shows us objects in the vast distances of space behind it. The transparent red sections of the nebula are filled with distant <a href="https://www.earth.com/news/galaxies-have-hearts-and-lungs-that-help-them-live-longer/" target="_blank" rel="noreferrer noopener">galaxies</a>.



“Look for the bright angled line at the upper left. It is not starlight - it is a faraway galaxy seen edge-on. Distant spirals, of many shapes and colors, also dot the scene. Those that are farthest away - or very dusty - are small and red,” said ESA.



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



Vela is a southern constellation that represents the sails of a ship. It was once part of a larger constellation called Argo Navis, which depicted the ship of the mythological hero Jason and the Argonauts. 



In the 18th century, Argo Navis was divided into three separate constellations: Vela (the sails), Carina (the keel), and Puppis (the stern).



Vela is notable for containing several interesting astronomical features. One of its most prominent stars is Gamma Velorum, also known as Suhail or Regor, which is a bright, massive star system consisting of multiple stars.&nbsp;



The constellation also hosts the Vela Supernova Remnant, the remains of a <a href="https://www.earth.com/news/supernova-explosions-could-damage-distant-planets/" target="_blank" rel="noreferrer noopener">supernova</a> explosion that occurred about 11,000 years ago. 



This remnant is associated with the Vela Pulsar, a neutron star that formed during the supernova explosion, which is one of the brightest pulsars in the sky.



Vela is best observed in the Southern Hemisphere, where it can be seen in the summer months. Its position along the Milky Way makes it a popular region for both amateur and professional astronomers to explore.



Image Credit: NASA, ESA, CSA, STScI



-----



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



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



-----

Southern Ring Nebula in the constellation Vela 

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. 



<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; to map the distribution of different stellar populations and identify regions of active star formation; and to investigate the underlying physics of spiral galaxy structures.&nbsp;



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-spiral-galaxies">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. Pavo is not visible from most of the northern hemisphere, but it can be seen from the southern hemisphere, particularly during the winter months.



The constellation 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;



-----



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



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



-----

Spiral galaxy NGC 6744 in the constellation Pavo

Today's Image of the Day from the European Space Agency features the Little Dumbbell Nebula, also known as Messier 76, located in the constellation Perseus 3,400 light-years away from Earth.



Astronomers captured this 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 (<a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">ESA</a>).



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.



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



Messier 76 is categorized as a planetary nebula - a term which refers to 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>. 



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.



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



The structure of Messier 76 is particularly notable. It includes a central ring, 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. 



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.



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



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. This heat is estimated to be 120,000 degrees Celsius - about 24 times hotter than the surface of our Sun. 



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.



<h2 class="wp-block-heading" id="h-powerful-glow-of-messier-76">Powerful glow of Messier 76</h2>



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;



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.&nbsp;



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.



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



Despite its current brilliance, the existence of the Little Dumbbell Nebula is fleeting on a cosmological scale. It is 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>. 



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.



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



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.



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.



Studying 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.



Image Credit: ESA Space Agency&nbsp;



-----



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



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



-----

Secrets of the Little Dumbbell Nebula  

When we think of oxytocin, the image of a warm embrace or the deep connection between a mother and her child often comes to mind. 



This hormone, often dubbed the "love hormone" or "cuddle hormone," is famous for its role in fostering emotional bonds and promoting feelings of trust and empathy. 



But recent studies suggest that oxytocin might be doing much more behind the scenes, especially when it comes to how we learn and remember. And more surprisingly, it may also help cure addiction.



Leading this exciting exploration are Professor Akiyoshi Saitoh and researcher Junpei Takahashi from the <a href="https://www.tus.ac.jp/en/" target="_blank" rel="noreferrer noopener">Tokyo University of Science</a>, and Meredith Berry, Ph.D. from the <a href="http://www.ufl.edu/" target="_blank" rel="noreferrer noopener">University of Florida</a>. 



They have been delving into the intricate ways oxytocin influences our brains, potentially paving the way for new treatments for conditions like dementia and <a href="https://www.earth.com/news/brain-discovery-offers-hope-for-tackling-opioid-addiction/" target="_blank" rel="noreferrer noopener">opioid addiction</a>.



<h2 class="wp-block-heading" id="h-oxytocin-s-role-in-memory">Oxytocin's role in memory</h2>



While oxytocin is well-known for its impact on social behaviors, its role in cognitive functions is less understood. 



Professor Saitoh's team wanted to uncover whether oxytocin could be a key player in <a href="https://www.earth.com/news/how-does-our-brain-form-long-term-memories/" target="_blank" rel="noreferrer noopener">how memories are formed</a> and retained. 



“Previously we had suggested that oxytocin may be a new therapeutic candidate for dementia based on studies using a mouse model of <a href="https://www.earth.com/news/alzheimers-disease-attacks-the-brain-in-two-separate-phases/" target="_blank" rel="noreferrer noopener">Alzheimer’s disease</a>,” he shared. 



“To investigate this further, in this study, we examined the role of endogenous oxytocin in mouse cognitive function.”



Using advanced techniques, the researchers specifically activated oxytocin neurons in certain brain regions of mice. 



They then evaluated the mice's memory using tasks designed to test recognition and recall, like the <a href="https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/novel-object-recognition-test" target="_blank" rel="noreferrer noopener">Novel Object Recognition Task</a>. 



This method helps scientists determine how well an animal can recognize a new object compared to one they've seen before.



<h2 class="wp-block-heading" id="h-peering-into-the-brain-s-memory-centers">Peering into the brain's memory centers</h2>



The brain is a complex network, and understanding how different areas interact is crucial. 



The team noticed that when they stimulated oxytocin neurons in the paraventricular hypothalamic nucleus (PVN), there was increased activity not only there but also in the supramammillary nucleus (SuM). 



These regions are connected and play roles in memory and <a href="https://www.earth.com/news/music-causes-similar-emotional-experiences-and-sensations-in-all-cultures/" target="_blank" rel="noreferrer noopener">emotional responses</a>.



By observing markers that indicate neuron activation, they confirmed that these areas were more active following their interventions. 



Interestingly, while the mice didn't show significant changes in short-term memory tasks, there was a noticeable improvement in long-term memory, particularly in recognizing new objects.



<h2 class="wp-block-heading" id="h-oxytocin-connection-to-dementia">Oxytocin connection to dementia</h2>



These findings have significant implications. <a href="https://www.earth.com/news/herbal-medicine-shows-potential-to-treat-and-prevent-dementia/" target="_blank" rel="noreferrer noopener">Dementia</a>, including Alzheimer's disease, affects millions worldwide, leading to memory loss and cognitive decline. 



Understanding how oxytocin influences memory could lead to new therapies that slow down or mitigate these effects.



There's also a broader social context. Many believe that loneliness and lack of social interaction can worsen <a href="https://www.earth.com/news/dementia-was-extremely-rare-in-ancient-times-so-why-is-it-now-so-prevalent/" target="_blank" rel="noreferrer noopener">dementia symptoms</a>. 



“There is a widely acknowledged belief that dementia tends to advance more rapidly in settings where individuals experience loneliness or limited social engagement. However, the scientific underpinnings of this phenomenon have remained largely elusive," Professor Saitoh pointed out.



By highlighting oxytocin's role, the research suggests that stimulating social interactions -- or even directly targeting oxytocin pathways -- might help in <a href="https://www.earth.com/news/diabetes-drugs-may-protect-against-dementia/" target="_blank" rel="noreferrer noopener">managing dementia</a>.



<h2 class="wp-block-heading" id="h-oxytocin-and-opioid-addiction">Oxytocin and opioid addiction</h2>



Across the globe, another team is exploring oxytocin's potential in a different arena. 



At the University of Florida, researchers are investigating whether a synthetic version of oxytocin can help curb opioid addictions, a pressing issue affecting many communities.



“The idea is that physicians could potentially prescribe, in combination, an opioid and oxytocin as an acute <a href="https://www.earth.com/news/mindfulness-meditation-is-a-powerful-weapon-against-chronic-pain/" target="_blank" rel="noreferrer noopener">pain management</a> option, while at the same time lessening the likelihood of developing an addiction to opioids,” explained Dr. Meredith Berry.



Working alongside Dr. Yenisel Cruz-Almeida and Dr. Natalie Ebner, Dr. Berry is examining whether oxytocin can reduce pain effectively while also decreasing the desire for prolonged opioid use.



<h2 class="wp-block-heading" id="h-opioids-are-still-a-huge-problem">Opioids are still a huge problem</h2>



Opioid addiction has become a significant public health concern, particularly in the United States. 



Prescription opioids, while effective for managing pain, carry a high risk of addiction. Older adults, who often require pain management, can be particularly vulnerable.



By exploring alternatives that reduce pain without the same addictive potential, researchers hope to offer safer options for patients. 



Oxytocin's natural role in promoting well-being might counteract some of the addictive properties of opioids.



<h2 class="wp-block-heading" id="h-healing-addiction-with-oxytocin">Healing addiction with oxytocin</h2>



In their carefully designed study, the University of Florida team is working with participants aged 55 to 85 who have some history of opioid use. 



In a controlled setting, these participants will receive synthetic oxytocin via a nasal spray or a placebo after taking oral <a href="https://www.earth.com/news/experts-identify-a-route-to-safer-painkillers/" target="_blank" rel="noreferrer noopener">oxycodone</a>.



The researchers will collect data on how much the participants enjoy the drugs, as well as monitor physical responses like heart rate and breathing. 



They'll also assess cognitive and emotional reactions. To measure pain responses, they will apply mild mechanical pressure to the thighs and expose the hands to varying temperatures.



Dr. Ebner will analyze mood changes and cognitive effects, while Dr. Cruz-Almeida will examine how the drugs affect pain responses. 



Dr. Berry will evaluate the potential for reduced opioid addiction based on these findings. Physicians from the university's College of Medicine are involved to ensure participant safety.



<h2 class="wp-block-heading" id="h-is-oxytocin-the-wonder-drug-of-the-future">Is oxytocin the "wonder drug" of the future?</h2>



The combined efforts of these research teams highlight the versatility of oxytocin, putting the "love hormone" on the radar of scientists of all disciplines around the world.



From potentially enhancing memory and combating dementia to offering new strategies for pain management without the high risk of addiction, oxytocin's benefits could be far-reaching.



These studies underscore the importance of looking beyond traditional uses of well-known substances. Sometimes, the key to solving complex health issues lies in re-examining what we thought we knew.



The journey of oxytocin from a simple "love hormone" to a potential powerhouse in medical treatment is a testament to the ever-evolving nature of science. 



As researchers like Professor Saitoh and Dr. Berry continue their work, we can look forward to new discoveries that might improve the quality of life for many.



The full study was published in the journal <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0294113" target="_blank" rel="noreferrer noopener">PLOS One</a>.



-----



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



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



-----

'Cuddle hormone' fosters love, boosts memory, and now also cures addiction

When we think of oxytocin, the image of a warm...

Scientists have uncovered a disturbing twist in how climate change affects our oceans, revealing that tiny changes at the bottom of the food chain can have massive impacts on most fish populations.



The findings of a recent study highlight the intricate workings of the ocean's food web and how it's more vulnerable to warming temperatures than previously thought.



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



<a href="https://www.earth.com/news/arctic-heatwaves-have-complex-effects-on-phytoplankton-food-web/" target="_blank" rel="noreferrer noopener">Phytoplankton</a> are tiny, plant-like organisms that float around in oceans, seas, and lakes. Even though you can't see them without a microscope, they're incredibly important. 



They use sunlight to make their own food through photosynthesis, just like plants do on land. In the process, they produce a huge amount of the Earth's oxygen -- some estimates say up to half of it. 



These little guys are the starting point of the food chain in aquatic environments, feeding small fish, shrimp, and other marine creatures.



<a href="https://www.earth.com/news/dust-from-africa-sparked-a-massive-phytoplankton-bloom/" target="_blank" rel="noreferrer noopener">Phytoplankton</a> also play a big role in absorbing carbon dioxide from the atmosphere, helping to regulate our planet's climate. But they're sensitive to changes in their environment, like warming waters.



When climate models predict that warming oceans will reduce phytoplankton levels by 16% to 26% in regions like the North Atlantic, it's a cause for concern.



But here's where it gets alarming: the study found that this seemingly modest drop in phytoplankton could slash the ocean's capacity to support fish by a staggering 38% to 55%. That's more than double the initial decrease in phytoplankton.



<h2 class="wp-block-heading" id="h-phytoplankton-and-the-hidden-amplifier">Phytoplankton and the hidden amplifier</h2>



Dr. Angus Atkinson from the <a href="https://pml.ac.uk/" target="_blank" rel="noreferrer noopener">Plymouth Marine Laboratory</a> and Dr. Axel Rossberg of <a href="https://www.qmul.ac.uk/" target="_blank" rel="noreferrer noopener">Queen Mary University</a> of London led the research team behind this discovery.



They took a straightforward approach by examining real-world data on plankton sizes from oceans, seas, and lakes around the globe. 



By looking at the sizes of plankton, they could determine how efficiently energy moves up the food chain -- from tiny phytoplankton to the fish we rely on.



This amplification effect hinges on a surprising twist: temperature, often blamed for food web disruptions, appears to play a secondary role. 



Instead, the key driver is the overall amount of phytoplankton, which governs how efficiently energy flows from tiny plankton to larger fish.



"Our global analysis sheds light on a hidden vulnerability," explained Dr. Atkinson. "We were surprised to find temperature didn't directly affect food web efficiency. Instead, we see ecosystems <a href="https://www.earth.com/news/invisible-forest-of-phytoplankton-thrives-in-a-warming-climate/" target="_blank" rel="noreferrer noopener">adapting to warming</a> by changing plankton size. "



<h2 class="wp-block-heading" id="h-nutrients-the-unsung-hero">Nutrients: The unsung hero</h2>



In the open ocean, nutrients come from deeper waters. As the surface warms, it becomes more layered, making it harder for these nutrients to reach the <a href="https://www.earth.com/image/spectacular-phytoplankton-bloom-in-the-north-atlantic/" target="_blank" rel="noreferrer noopener">phytoplankton at the top</a>.



"Close to shore or in lakes, excess nutrients from land can cause imbalances like harmful algal blooms," notes Dr. Rossberg. 



"But at the vast scales relevant to climate change, it's the lack of nutrients from deeper waters that becomes the major bottleneck."



To clarify, warming oceans, seas, and lakes impact fish indirectly by reducing nutrient supply from <a href="https://www.earth.com/news/toxic-legacy-decades-old-ddt-found-in-deep-sea-fish/" target="_blank" rel="noreferrer noopener">deeper waters</a>, ultimately shrinking phytoplankton size and hindering energy transfer throughout the food web.



<h2 class="wp-block-heading" id="h-real-world-impact-for-ocean-fish">Real world impact for ocean fish</h2>



When phytoplankton numbers change, the impact can ripple through the entire <a href="https://www.earth.com/news/oceans-twilight-zone-stabilizes-the-marine-food-chain/" target="_blank" rel="noreferrer noopener">marine ecosystem</a>, impacting everything from water quality to the abundance of fish.



This isn't just a problem for the fish; it's a problem the planet. Many communities around the world depend on fishing for food and livelihood. 



The study highlights the need to consider climate change impacts when managing fisheries.



"Global averages can mask the true picture," explains Dr. Atkinson. "Some of the most significant projected declines are in areas with concentrated <a href="https://www.earth.com/news/fish-stocks-are-collapsing-globally-as-overfishing-continues/" target="_blank" rel="noreferrer noopener">fishing activities</a>."



<h2 class="wp-block-heading" id="h-what-happens-next">What happens next?</h2>



So, what can we do about it? The researchers suggest a multi-pronged approach to ensure sustainable fisheries in the face of climate change. 



"We need a combination of data on plankton size structure and sophisticated computer simulation models to design truly 'climate-smart' ocean protection strategies," concludes Dr. Rossberg. 



"By understanding the hidden amplifiers within the food web, we can better safeguard the future of our oceans and the vital resources they provide."



<h2 class="wp-block-heading" id="h-oceans-fish-and-the-global-food-chain">Oceans, fish, and the global food chain</h2>



To sum it all up, these scientists found that even a small drop in phytoplankton levels due to warming oceans can massively reduce fish populations. 



They discovered that it's not just the temperature rise itself causing problems, but the decrease in nutrients reaching these tiny organisms. 



This leads to smaller plankton and less efficient energy transfer <a href="https://www.earth.com/news/microbial-awakening-arctic-food-webs-are-transforming-from-green-to-brown/" target="_blank" rel="noreferrer noopener">up the food chain</a>, which is bad news for fish and, by extension, us.



This study underscores underscores the interconnectedness of Earth's ecosystem. Tiny changes at the bottom can have huge impacts at the top. 



It's a reminder that we need to pay attention to even the smallest players in the ecosystem if we want to protect the health of our planet. 



By understanding these hidden mechanisms, we can work towards smarter strategies to safeguard our oceans and the communities that rely on them.



The full study was published in the journal <a href="https://www.nature.com/articles/s41467-023-44406-5" target="_blank" rel="noreferrer noopener">Nature Communications</a>.



-----



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



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



-----

Oceans and lakes are quickly losing their ability to keep fish alive

Scientists have uncovered a disturbing twist in how climate change...

The development of a big brain in humans and its connection to social bonding has been a hot topic of debate, and secrets found in fossil teeth may hold the answers.



Researchers have been studying the fossilized teeth of an early Homo from Georgia, dating back approximately 1.77 million years. The research was made possible by the European Synchrotron in Grenoble, France.



The findings suggest that despite having a small brain and reaching adulthood at a similar pace to great apes, these early humans had a prolonged childhood. 



This could mean that the large brain of modern humans resulted from an extended childhood along with cultural transmission across generations instead of vice versa.



<h2 class="wp-block-heading" id="h-long-childhood-big-brains">Long childhood, big brains</h2>



A team of researchers - including specialists from Switzerland's <a href="https://www.uzh.ch/en.html" target="_blank" rel="noreferrer noopener">University of Zurich</a>, the European Synchrotron Radiation Facility and Georgia's National Museum - have challenged the theory that modern humans' extended childhood is directly linked to their large brains.



The team analyzed dental development in an early Homo that was almost an adult. The results suggest that though these early humans reached adulthood at a similar age as <a href="https://www.earth.com/news/buronius-manfredschmidi-tiny-great-ape-species-lived-11-million-years-ago/" target="_blank" rel="noreferrer noopener">great apes</a>, their tooth development followed a longer timeline similar to modern humans.



This proposes the distinct possibility of a longer dependency on adults and an elongated childhood for these early humans.



Remarkably, the brain size of these early Homo specimens was only marginally larger than that of a chimpanzee. This made the researchers question the link between the prolonged development and cultural transmission across generations.



An extended childhood within a three-generation context might have allowed the immature members of the group to effectively assimilate growing amounts of knowledge. 



Eventually, this led to the development of larger brains and longer life spans, traits characteristic of modern humans.



<h2 class="wp-block-heading" id="h-dental-development-in-early-homo">Dental development in early Homo</h2>



An enduring assumption has been that humans' extended growth period is a consequence of <a href="https://www.earth.com/news/our-brain-sizes-are-growing-possibly-lowering-dementia-risk/" target="_blank" rel="noreferrer noopener">increased brain volume</a> since a larger organ requires more energy resources to grow. But analysis of the fossil's dental growth has caused researchers to question this hypothesis.



The research team used synchrotron imaging to study the dental development of a near-adult fossil of early Homo from the Dmanisi site in Georgia, dated to around 1.77 million years ago. 



<div class="wp-block-sendtonews-playerselector">[sendtonews key="CWxiqQg039-4024544-12187" type="single"]</div>



“Childhood and cognition do not fossilize, so we have to rely on indirect information. Teeth are ideal because they fossilize well and produce daily rings, in the same way that trees produce annual rings, which record their development,” noted study first author Christoph Zollikofer from the University of Zurich.



<h2 class="wp-block-heading" id="h-unexpected-findings-and-a-new-perspective">Unexpected findings and a new perspective</h2>



“Dental development is strongly correlated with the development of the rest of the body, including brain development," explained study co-author Paul Tafforeau, scientist at the ESRF.



"Access to the details of a <a href="https://www.earth.com/search-results/?search=fossil%20hominid&amp;start=0" target="_blank" rel="noreferrer noopener">fossil</a> hominid's dental growth therefore provides a great deal of information about its general growth."



After almost two decades of research beginning in 2005, the initial results startled researchers. 



“We expected to find either dental development typical of early hominids, close to that of the great apes, or dental development close to that of <a href="https://www.earth.com/news/neanderthal-genes-still-influence-modern-humans/" target="_blank" rel="noreferrer noopener">modern humans</a>," said Tafforeau.



"When we obtained the first results, we couldn’t believe what we saw, because it was something different that implied faster molar crown growth than in any other fossil hominin or living great ape."



In the following years, the team conducted five series of experiments and completed four full analyses, employing various methods as dental synchrotron imaging technology advanced.



As the consistent results suggested significant implications for the "big brain - long childhood" hypothesis, the scientists needed to think creatively to interpret this fossil's findings.



“It's been a slow maturation, both technically and intellectually, to finally arrive at the hypothesis we are publishing today,” said Tafforeau.



<h2 class="wp-block-heading" id="h-longer-childhood-evolution-s-early-experiment">Longer childhood: Evolution's early experiment?</h2>



The dental development of the studied fossil suggested that milk teeth were used longer than in great apes, implying that early Homo children were dependent on adult care for a longer duration.



This could be the first experiment evolution took towards a prolonged childhood. Despite having brains only slightly larger than australopithecines or great apes, early Homo are believed to have lived longer.



The survival of a very old individual with no teeth for several years indicates that the group sufficiently cared for him. This alludes to a three-generation structure, a key aspect of <a href="https://www.earth.com/news/humans-started-cumulative-culture-around-600000-years-ago/" target="_blank" rel="noreferrer noopener">cultural transmission in humans</a>.



The new hypothesis begins with children's growth slowing down as cultural transmission increased. 



The accumulation of information from older to younger individuals had an advantageous effect on resource utilization and the development of complex behaviors, thus favoring a longer childhood. 



Once this mechanism was established, natural selection acted on cultural transmission, not just biological traits. 



<h2 class="wp-block-heading" id="h-big-brains-and-delayed-adulthood">Big brains and delayed adulthood</h2>



As the volume of transferrable information grew, evolution supported a larger brain and delayed adulthood, enabling a longer learning period in childhood and time to grow a bigger brain despite limited food resources.



The large brain of modern humans could be attributed to an extended childhood and a three-generation structure encouraging bio-cultural evolution. These mechanisms may have led to increased brain size, delayed adulthood, and longer lifespan. 



The study of this exceptional fossil could motivate researchers to rethink the evolutionary mechanisms that led to Homo sapiens.



The study is published in the journal <a href="https://www.nature.com/articles/s41586-024-08205-2" target="_blank" rel="noreferrer noopener">Nature</a>.



Image &amp; Video Credit: ESRF/Paul Tafforeau, Vincent Beyrand



-----



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



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



-----

How did humans get big brains? Fossil teeth reveal new clues

The development of a big brain in humans and its...

Earth from Space is presented by Kelsea Brennan-Wessels from the ESA Web-TV virtual studios. The one hundred twenty-fourth edition features A Sentinel-1A radar image of Tokyo Bay.
&#8212;
Credit: <a href="http://www.esa.int" target="_blank" rel="noopener">ESA</a>

Earth From Space: Megacity Of Tokyo And Tokyo Bay