juliensimon/nasa-apod huggingface dataset:
Gum 37 and the Southern Tadpoles (2025-04-28)

This cosmic skyscape features glowing gas and dark dust clouds alongside the young stars of NGC 3572.  A beautiful emission nebula and star cluster, it sails far southern skies within the nautical constellation Carina.  Stars from NGC 3572 are toward top center in the telescopic frame that would measure about 100 light-years across at the cluster's estimated distance of 9,000 light-years.  The visible interstellar gas and dust, shown in colors of the Hubble palette, is part of the star cluster's natal molecular cloud, itself cataloged as Gum 37. Dense streamers of material within the nebula, eroded by stellar winds and radiation, clearly trail away from the energetic young stars.  They are likely sites of ongoing star formation with shapes reminiscent of the Tadpoles of IC 410 -- better known to northern skygazers.  In the coming tens to hundreds of millions of years, gas and stars in the cluster will be dispersed though, by gravitational tides and by violent supernova explosions that end the short lives of the massive cluster stars.

Image credit: Francis Bozon & Cecil Navick
(AstroA. R. O.)
Saturn's Rings Appear to Disappear (2025-04-29)

Where are Saturn's ears? Galileo is credited, in 1610, as the first person to see Saturn's rings. Testing out Lipperhey's recently co-invented telescope, Galileo did not know what they were and so called them "ears".  The mystery deepened in 1612, when Saturn's ears mysteriously disappeared. Today we know exactly what happened: from the perspective of the Earth, Saturn's rings had become too thin to see.  The same drama plays out every 15 years because Saturn, like Earth, undergoes tilt-driven seasons. This means that as Saturn goes around the Sun, its equator and rings can tilt noticeably toward the Sun and inner Solar System, making them easily visible, but from other orbital locations will appear almost not at all.  The featured picture from Brasilia, Brazil shows a modern version of this sequence: the top ring-dominated image was taken in 2020, while the bottom ring-obscure image taken earlier in 2025.   Make Saturn's Rings Musical: Play them like a harp!

Image credit: Natan Fontes
A Happy Sky over Bufa Hill in Mexico (2025-04-30)

Sometimes, the sky itself seems to smile.  A few days ago, visible over much of the world, an unusual superposition of our Moon with the planets Venus and Saturn created just such an iconic facial expression. Specifically, a crescent Moon appeared to make a happy face on the night sky when paired with seemingly nearby planets.  Pictured is the scene as it appeared over Zacatecas, México, with distinctive Bufa Hill in the foreground.  On the far right and farthest in the distance is the planet Saturn.  Significantly closer and visible to Saturn's upper left is Venus, the brightest planet on the sky.  Just above the central horizon is Earth's Moon in a waning crescent phase. To create this gigantic icon, the crescent moon phase must be smiling in the correct direction.   Dial-A-Moon: Find the Moon phase on your birthday this year

Image credit: Daniel Korona
MESSENGER's Last Day on Mercury (2025-05-01)

The first to orbit inner planet Mercury, the MESSENGER spacecraft came to rest on this region of Mercury's surface on April 30, 2015. Constructed from MESSENGER image and laser altimeter data, the projected scene looks north over the northeastern rim of the broad, lava filled Shakespeare basin. The large, 48 kilometer (30 mile) wide crater Janacek is near the upper left edge. Terrain height is color coded with red regions about 3 kilometers above blue ones. MESSENGER'S final orbit was predicted to end near the center, with the spacecraft impacting the surface at nearly 4 kilometers per second (over 8,700 miles per hour) and creating a new crater about 16 meters (52 feet) in diameter. The impact on the far side of Mercury was not observed by telescopes, but confirmed when no signal was detected from the spacecraft given time to emerge from behind the planet. Launched in 2004, the MErcury Surface, Space ENvironment, GEochemisty and Ranging spacecraft completed over 4,000 orbits after reaching the Solar System's innermost planet in 2011.
Young Star Cluster NGC 346 (2025-05-02)

The most massive young star cluster in the Small Magellanic Cloud is NGC 346, embedded in our small satellite galaxy's largest star forming region some 210,000 light-years distant. Of course the massive stars of NGC 346 are short lived, but very energetic.  Their winds and radiation sculpt the edges of the region's dusty molecular cloud triggering star-formation within. The star forming region also appears to contain a large population of infant stars. A mere 3 to 5 million years old and not yet burning hydrogen in their cores, the infant stars are strewn about the embedded star cluster. This spectacular infrared view of NGC 346 is from the James Webb Space Telescope's NIRcam. Emission from atomic hydrogen ionized by the massive stars' energetic radiation as well as molecular hydrogen and dust in the star-forming molecular cloud is detailed in pink and orange hues. Webb's sharp image of the young star-forming region spans 240 light-years at the distance of the Small Magellanic Cloud.
Titan: Moon over Saturn (2025-05-03)

Like Earth's moon, Saturn's largest moon Titan is locked in synchronous rotation with its planet. This mosaic of images recorded by the Cassini spacecraft in May of 2012 shows its anti-Saturn side, the side always facing away from the ringed gas giant. The only moon in the solar system with a dense atmosphere, Titan is the only solar system world besides Earth known to have standing bodies of liquid on its surface and an earthlike cycle of liquid rain and evaporation. Its high altitude layer of atmospheric haze is evident in the Cassini view of the 5,000 kilometer diameter moon over Saturn's rings and cloud tops. Near center is the dark dune-filled region known as Shangri-La. The Cassini-delivered Huygens probe rests below and left of center, after the most distant landing for a spacecraft from Earth.
Spin up of a Supermassive Black Hole (2025-05-04)

How fast can a black hole spin?  If any object made of regular matter spins too fast -- it breaks apart. But a black hole might not be able to break apart -- and its maximum spin rate is really unknown. Theorists usually model rapidly rotating black holes with the Kerr solution to Einstein's General Theory of Relativity, which predicts several amazing and unusual things.  Perhaps its most easily testable prediction, though, is that matter entering a maximally rotating black hole should be last seen orbiting at near the speed of light, as seen from far away. This prediction was tested by NASA's NuSTAR and ESA's XMM satellites by observing the supermassive black hole at the center of spiral galaxy NGC 1365. The near light-speed limit was confirmed by measuring the heating and spectral line broadening of nuclear emissions at the inner edge of the surrounding accretion disk. Pictured here is an artist's illustration depicting an accretion disk of normal matter swirling around a black hole, with a jet emanating from the top. Since matter randomly falling into the black hole should not spin up a black hole this much, the NuSTAR and XMM measurements also validate the existence of the  surrounding accretion disk.   Hole New Worlds: It's Black Hole Week at NASA!
Planet Lines Across Water (2025-05-05)

What’s causing those lines? Objects in the sky sometimes appear reflected as lines across water — but why? If the water’s surface is smooth, then reflected objects would appear similarly -- as spots. But if the water is choppy, then there are many places where light from the object can reflect off the water and still come to you -- and so together form, typically, a line. The same effect is frequently seen for the Sun just before sunset and just after sunrise. Pictured about 10 days ago in Ibiza, Spain, images of the rising Moon, Venus (top), and Saturn (right, faint) were captured both directly and in line-reflected forms from the Mediterranean Sea. The other bright object on the right with a water-reflected line is a beacon on a rock to warn passing boats.   Explore Your Universe: Random APOD Generator

Image credit: Jose Antonio Hervas
The Doubly Warped World of Binary Black Holes (2025-05-06)

If one black hole looks strange, what about two? Light rays from accretion disks around a pair of orbiting supermassive black holes make their way through the warped space-time produced by extreme gravity in this detailed computer visualization.  The simulated accretion disks have been given different false color schemes, red for the disk surrounding a 200-million-solar-mass black hole, and blue for the disk surrounding a 100-million-solar-mass black hole.  For these masses, though, both accretion disks would actually emit most of their light in the ultraviolet.  The video allows us to see both sides of each black hole at the same time.  Red and blue light originating from both black holes can be seen in the innermost ring of light, called the photon sphere, near their event horizons.  In the past decade, gravitational waves from black hole collisions have actually been detected, although the coalescence of supermassive black holes remains undiscovered.   Hole New Worlds: It's Black Hole Week at NASA!
Galaxy Wars: M81 versus M82 (2025-05-07)

In the upper left corner, surrounded by blue arms and dotted with red nebulas, is spiral galaxy M81.  In the lower right corner, marked by a light central line and surrounded by red glowing gas, is irregular galaxy M82.  This stunning vista shows these two mammoth galaxies locked in gravitational combat, as they have been for the past billion years.   The gravity from each galaxy dramatically affects the other during each hundred-million-year pass.  Last go-round, M82's gravity likely raised density waves rippling around M81, resulting in the richness of M81's spiral arms.  But M81 left M82 with violent star forming regions and colliding gas clouds so energetic the galaxy glows in X-rays.  This big battle is seen from Earth through the faint glow of an Integrated Flux Nebula, a little studied complex of diffuse gas and dust clouds in our Milky Way Galaxy. In a few billion years, only one galaxy will remain.

Image credit: Collaborative Astrophotography Team (CAT)
M1: The Incredible Expanding Crab (2025-05-08)

Cataloged as M1, the Crab Nebula is the first on Charles Messier's famous list of things which are not comets. In fact, the Crab Nebula is now known to be a supernova remnant, an expanding cloud of debris from the death explosion of a massive star. The violent birth of the Crab was witnessed by astronomers in the year 1054. Roughly 10 light-years across, the nebula is still expanding at a rate of about 1,500 kilometers per second. You can see the expansion by comparing these sharp images from the Hubble Space Telescope and James Webb Space Telescope. The Crab's dynamic, fragmented filaments were captured in visible light by Hubble in 2005 and Webb in infrared light in 2023. This cosmic crustacean lies about 6,500 light-years away in the constellation Taurus.
IXPE Explores a Black Hole Jet (2025-05-09)

How do black holes create X-rays? Answering this long-standing question was significantly advanced recently with data taken by NASA’s IXPE satellite. X-rays cannot exit a black hole, but they can be created in the energetic environment nearby, in particular by a jet of particles moving outward. By observing X-ray light arriving from near the supermassive black hole at the center of galaxy BL Lac, called a blazar, it was discovered that these X-rays lacked significant polarization, which is expected when created more by energetic electrons than protons. In the featured artistic illustration, a powerful jet is depicted emanating from an orange-colored accretion disk circling the black hole. Understanding highly energetic processes across the universe helps humanity to understand similar processes that occur on or near our Earth.   Put it All Together: Astronomy Puzzle of the Day
Yogi and Friends in 3D (2025-05-10)

This picture from July 1997 shows a ramp from the Pathfinder lander, the Sojourner robot rover, deflated landing airbags, a couch, Barnacle Bill and Yogi Rock appear together in this 3D stereo view of the surface of Mars. Barnacle Bill is the rock just left of the house cat-sized, solar-paneled Sojourner. Yogi is the big friendly-looking boulder at top right. The "couch" is the angular rock shape visible near center on the horizon. Look at the image with red/blue glasses (or just hold a piece of clear red plastic over your left eye and blue or green over your right) to get the dramatic 3D perspective. The stereo view was recorded by the remarkable Imager for Mars Pathfinder (IMP) camera. The IMP had two optical paths for stereo imaging and ranging and was equipped with an array of color filters for spectral analysis.  Operating as the first astronomical observatory on Mars, the IMP also recorded images of the Sun and Deimos, the smallest of Mars' two tiny moons.
The Surface of Venus from Venera 14 (2025-05-11)

If you could stand on Venus -- what would you see?  Pictured is the view from Venera 14, a robotic Soviet lander which parachuted and air-braked down through the thick Venusian atmosphere in March of 1982. The desolate landscape it saw included flat rocks, vast empty terrain, and a featureless sky above Phoebe Regio near Venus' equator. On the lower left is the spacecraft's penetrometer used to make scientific measurements, while the light piece on the right is part of an ejected lens-cap.  Enduring temperatures near 450 degrees Celsius and pressures 75 times that on Earth, the hardened Venera spacecraft lasted only about an hour. Although data from Venera 14 was beamed across the inner Solar System over 40 years ago, digital processing and merging of Venera's unusual images continues even today.  Recent analyses of infrared measurements taken by ESA's orbiting Venus Express spacecraft indicate that active volcanoes may currently exist on Venus.    Jigsaw Fun: Astronomy Puzzle of the Day

Image credit: Donald Mitchell
Gaia Reconstructs a Side View of our Galaxy (2025-05-12)

What does our Milky Way Galaxy look like from the side? Because we are on the inside, humanity can’t get an actual picture. Recently, however, just such a map has been made using location data for over a billion stars from ESA’s Gaia mission. The resulting featured illustration shows that just like many other spiral galaxies, our Milky Way has a very thin central disk. Our Sun and all the stars we see at night are in this disk. Although hypothesized before, perhaps more surprising is that the disk appears curved at the outer edges. The colors of our Galaxy's warped central band derive mostly from dark dust, bright blue stars, and red emission nebulas. Although data analysis is ongoing, Gaia was deactivated in March after a successful mission.   Explore Your Universe: Random APOD Generator
Gaia Reconstructs a Top View of our Galaxy (2025-05-13)

What does our Milky Way Galaxy look like from the top? Because we are on the inside, humanity can’t get an actual picture. Recently, however, just such a map has been made using location data for over a billion stars from ESA’s Gaia mission. The resulting featured illustration shows that just like many other spiral galaxies, our Milky Way has distinct spiral arms.  Our Sun and most of the bright stars we see at night are in just one arm: Orion. Gaia data bolsters previous indications that our Milky Way has more than two spiral arms. Our Galaxy's center sports a prominent bar.  The colors of our Galaxy's thin disk derive mostly from dark dust, bright blue stars, and red emission nebula. Although data analysis is ongoing, Gaia was deactivated in March after a successful mission.   Jigsaw Challenge: Astronomy Puzzle of the Day
NGC 1360: The Robin's Egg Nebula (2025-05-14)

This pretty nebula lies some 1,500 light-years away, its shape and color in this telescopic view reminiscent of a robin's egg. The cosmic cloud spans about 3 light-years, nestled securely within the boundaries of the southern constellation of the Furnace (Fornax). Recognized as a planetary nebula, egg-shaped NGC 1360 doesn't represent a beginning, though. Instead, it corresponds to a brief and final phase in the evolution of an aging star. In fact, visible at the center of the nebula, the central star of NGC 1360 is known to be a binary star system likely consisting of two evolved white dwarf stars, less massive but much hotter than the Sun.  Their intense and otherwise invisible ultraviolet radiation has stripped away electrons from the atoms in their mutually surrounding gaseous shroud. The blue-green hue inside of NGC 1360 seen here is the strong emission produced as electrons recombine with doubly ionized oxygen atoms.   Celestial Surprise: What picture did APOD feature on your birthday? (post 1995)

Image credit: Andrea Iorio, 
Vikas Chander & 
ShaRA Team
A Plutonian Landscape (2025-05-15)

This shadowy landscape of majestic mountains and icy plains stretches toward the horizon on a small, distant world. It was captured from a range of about 18,000 kilometers when New Horizons looked back toward Pluto, 15 minutes after the spacecraft's closest approach on July 14, 2015. The dramatic, low-angle, near-twilight scene follows rugged mountains formally known as Norgay Montes from foreground left, and Hillary Montes along the horizon, giving way to smooth Sputnik Planum at right. Layers of Pluto's tenuous atmosphere are also revealed in the backlit view. With a strangely familiar appearance, the frigid terrain likely includes ices of nitrogen and carbon monoxide with water-ice mountains rising up to 3,500 meters (11,000 feet). That's comparable in height to the majestic mountains of planet Earth. The Plutonian landscape is 380 kilometers (230 miles) across.
Messier 101 (2025-05-16)

Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way. M101 was also one of the original spiral nebulae observed by Lord Rosse's large 19th century telescope, the Leviathan of Parsontown. Assembled from 51 exposures recorded by the Hubble Space Telescope in the 20th and 21st centuries, with additional data from ground based telescopes, this mosaic spans about 40,000 light-years across the central region of M101 in one of the highest definition spiral galaxy portraits ever released from Hubble. The sharp image shows stunning features of the galaxy's face-on disk of stars and dust along with background galaxies, some visible right through M101 itself. Also known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major, about 25 million light-years away.
Ares 3 Landing Site: The Martian Revisited (2025-05-17)

This close-up from the Mars Reconnaissance Orbiter's HiRISE camera shows weathered craters and windblown deposits in southern Acidalia Planitia. A striking shade of blue in standard HiRISE image colors, to the human eye the area would probably look grey or a little reddish. But human eyes have not gazed across this terrain, unless you count the eyes of NASA astronauts in the sci-fi novel, "The Martian," by Andy Weir. The novel chronicles the adventures of Mark Watney, an astronaut stranded at the fictional Mars mission Ares 3 landing site, corresponding to the coordinates of this cropped HiRISE frame. For scale, Watney's 6-meter-diameter habitat at the site would be about 1/10th the diameter of the large crater. Of course, the Ares 3 landing coordinates are only about 800 kilometers north of the (real life) Carl Sagan Memorial Station, the 1997 Pathfinder landing site.
Pluto Flyover from New Horizons (2025-05-18)

What if you could fly over Pluto -- what might you see? The New Horizons spacecraft did just this in 2015 July as it shot past the distant world at a speed of about 80,000 kilometers per hour. Images from this spectacular passage have been color enhanced, vertically scaled, and digitally combined into the featured two-minute time-lapse video. As your journey begins, light dawns on mountains thought to be composed of water ice but colored by frozen nitrogen.  Soon, to your right, you see a flat sea of mostly solid nitrogen that has segmented into strange polygons that are thought to have bubbled up from a comparatively warm interior.  Craters and ice mountains are common sights below. The video dims and ends over terrain dubbed bladed because it shows 500-meter high ridges separated by kilometer-sized gaps.  The robotic New Horizons spacecraft has too much momentum to ever return to Pluto and is now headed out of our Solar System.
Charon Flyover from New Horizons (2025-05-19)

What if you could fly over Pluto's moon Charon -- what might you see? The New Horizons spacecraft did just this in 2015 July as it zipped past Pluto and Charon with cameras blazing.  The images recorded allowed for a digital reconstruction of much of Charon's surface, further enabling the creation of fictitious flights over Charon created from this data.  One such fanciful, minute-long, time-lapse video is shown here with vertical heights and colors of surface features digitally enhanced.  Your journey begins over a wide chasm that divides different types of Charon's landscapes, a chasm that might have formed when Charon froze through. You soon turn north and fly over a colorful depression dubbed Mordor that, one hypothesis holds, is an unusual remnant from an ancient impact.  Your voyage continues over an alien landscape rich with never-before-seen craters, mountains, and crevices.  The robotic New Horizons spacecraft has too much momentum to ever return to Pluto and Charon and is now headed out of our Solar System.    Portal Universe: Random APOD Generator
Milky Way over Maunakea (2025-05-20)

Have you ever seen the band of our Milky Way Galaxy?  In a clear sky from a dark location at the right time, a faint band of light becomes visible across the sky.  Soon after your eyes become dark adapted, you might spot the band for the first time.  It may then become obvious.  Then spectacular.  One reason for your growing astonishment might be the realization that this fuzzy swath, the Milky Way, contains billions of stars.  Visible in the featured image, high above in the night sky, the band of the Milky Way Galaxy arcs.  Also visible are the colorful clouds of Rho Ophiuchi on the right, and the red and circular Zeta Ophiuchi nebula near the top center. Taken in late February from Maunakea, Hawaii, USA, the foreground telescope is the University of Hawaii's 2.2-Meter Telescope. Fortunately, you don’t need to be near the top of a Hawaiian volcano to see the Milky Way.    Put it All Together: Astronomy Puzzle of the Day

Image credit: Marzena Rogozinska
International Space Station Crosses the Sun (2025-05-21)

Typically, the International Space Station is visible only at night.  Slowly drifting across the night sky as it orbits the Earth, the International Space Station (ISS) can be seen as a bright spot about once a month from many locations.  The ISS is then visible only just after sunset or just before sunrise because it shines by reflected sunlight -- once the ISS enters the Earth's shadow, it will drop out of sight. The only occasion when the ISS is visible during the day is when it passes right in front of the Sun. Then, it passes so quickly that only cameras taking short exposures can visually freeze the ISS's silhouette onto the background Sun. The featured picture did exactly that -- it is actually a series of images taken a month ago from Sant Feliu de Buixalleu, Spain with perfect timing.  This image series was later combined with a separate image highlighting the texture of the active Sun which included several Sun's prominences around the edge.   Celestial Surprise: What picture did APOD feature on your birthday? (post 1995)

Image credit: Pau Montplet Sanz