juliensimon/nasa-apod huggingface dataset:
SH2-308: The Dolphin Head Nebula (2024-06-07)

Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 2-308 it lies some 5,000 light-years away toward the well-trained constellation Canis Major and covers slightly more of the sky than a Full Moon. That corresponds to a diameter of 60 light-years at its estimated distance. The massive star that created the bubble, a Wolf-Rayet star, is the bright one near the center of the nebula. Wolf-Rayet stars have over 20 times the mass of the Sun and are thought to be in a brief, pre-supernova phase of massive star evolution. Fast winds from this Wolf-Rayet star create the bubble-shaped nebula as they sweep up slower moving material from an earlier phase of evolution. The windblown nebula has an age of about 70,000 years. Relatively faint emission captured by narrowband filters in the deep image is dominated by the glow of ionized oxygen atoms mapped to a blue hue. Presenting a mostly harmless outline, SH2-308 is also known as The Dolphin-head Nebula.

Image credit: Prabhu Kutti
Pandora's Cluster of Galaxies (2024-06-08)

This deep field mosaicked image presents a stunning view of galaxy cluster Abell 2744 recorded by the James Webb Space Telescope's NIRCam. Also dubbed Pandora's Cluster, Abell 2744 itself appears to be a ponderous merger of three different massive galaxy clusters. It lies some 3.5 billion light-years away, toward the constellation Sculptor. Dominated by dark matter, the mega-cluster warps and distorts the fabric of spacetime, gravitationally lensing even more distant objects. Redder than the Pandora cluster galaxies many of the lensed sources are very distant galaxies in the early Universe, their lensed images stretched and distorted into arcs. Of course distinctive diffraction spikes mark foreground Milky Way stars. At the Pandora Cluster's estimated distance this cosmic box spans about 6 million light-years. But don't panic. You can explore the tantalizing region in a 2 minute video tour.
How to Identify that Light in the Sky (2024-06-09)

What is that light in the sky? The answer to one of humanity's more common questions may emerge from a few quick observations.  For example -- is it moving or blinking? If so, and if you live near a city, the answer is typically an airplane, since planes are so numerous and so few stars and satellites are bright enough to be seen over the glare of artificial city lights. If not, and if you live far from a city, that bright light is likely a planet such as Venus or Mars -- the former of which is constrained to appear near the horizon just before dawn or after dusk.  Sometimes the low apparent motion of a distant airplane near the horizon makes it hard to tell from a bright planet, but even this can usually be discerned by the plane's motion over a few minutes. Still unsure?   The featured chart gives a sometimes-humorous but mostly-accurate assessment.  Dedicated sky enthusiasts will likely note -- and are encouraged to provide -- polite corrections.   Chart translations: Italian, German, Latvian, Persian, Polish, Slovenian, Spanish, and Turkish

Image credit: HK (The League of Lost Causes)
Sh2-132: The Lion Nebula (2024-06-10)

Is the Lion Nebula the real ruler of the constellation Cepheus?  This powerful feline appearing nebula is powered by two massive stars, each with a mass over 20 times greater than our Sun.  Formed from shells of ionized gas that have expanded, the nebula's energetic matter not only glows, but is dense enough to contract gravitationally and form stars.  The angular size of the Lion Nebula, officially named Sh2-132,  is slightly greater than that of the full moon.  The gaseous iconic region resides about 10,000 light years away in a constellation named after the King of Aethopia in Greek mythology.   Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

Image credit: Imran Badr;
Text: Natalia Lewandowska 
(SUNY Oswego)
Colorful Stars and Clouds near Rho Ophiuchi (2024-06-11)

Why is the sky near Antares and Rho Ophiuchi so colorful, yet dusty?  The colors result from a mixture of objects and processes.  Fine dust -- illuminated by starlight -- produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark.   Antares, a red supergiant and one of the brighter stars in the night sky, lights up the yellow-red clouds on the upper right of the featured image. The Rho Ophiuchi star system lies at the center of the blue reflection nebula on the left, while a different reflection nebula, IC 4605, lies just below and right of the image center.  These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum.   Open Science: Browse 3,400+ codes in the Astrophysics Source Code Library

Image credit: Craig Stocks
Aurora over Karkonosze Mountains (2024-06-12)

It was the first time ever. At least, the first time this photographer had ever seen aurora from his home mountains.  And what a spectacular aurora it was. The Karkonosze Mountains in Poland are usually too far south to see any auroras.  But on the amazing night of May 10 - 11, purple and green colors lit up much of the night sky, a surprising spectacle that  also appeared over many mid-latitude locations around the Earth.  The featured image is a composite of six vertical exposures taken during the auroral peak. The futuristic buildings on the right are part of a meteorological observatory located on the highest peak of the Karkonosze Mountains.  The purple color is primarily due to Sun-triggered, high-energy electrons impacting nitrogen molecules in Earth's atmosphere.  Our Sun is reaching its maximum surface activity over the next two years, and although many more auroras are predicted, most will occur over regions closer to the Earth's poles.

Image credit: Daniel Koszela
Messier 66 Close Up (2024-06-13)

Big, beautiful spiral galaxy Messier 66 lies a mere 35 million light-years away. The gorgeous island universe is about 100 thousand light-years across, similar in size to the Milky Way. This Hubble Space Telescope close-up view spans a region about 30,000 light-years wide around the galactic core. It shows the galaxy's disk dramatically inclined to our line-of-sight. Surrounding its bright core, the likely home of a supermassive black hole, obscuring dust lanes and young, blue star clusters sweep along spiral arms dotted with the tell-tale glow of pinkish star forming regions. Messier 66, also known as NGC 3627, is the brightest of the three galaxies in the gravitationally interacting Leo Triplet.
RCW 85 (2024-06-14)

From the 1960 astronomical catalog of Rodgers, Campbell and Whiteoak, emission region RCW 85 shines in southern night skies between bright stars Alpha and Beta Centauri. About 5,000 light years distant, the hazy interstellar cloud of glowing hydrogen gas and dust is faint. But detailed structures along well-defined rims within RCW 85 are traced in this cosmic skyscape composed of 28 hours of narrow and broadband exposures. Suggestive of dramatic shapes in other stellar nurseries where natal clouds of gas and dust are sculpted by energetic winds and radiation from newborn stars, the tantalizing nebula has been called the Devil's Tower. This telescopic frame would span around 100 light-years at the estimated distance of RCW 85.

Image credit: Martin Pugh
Prominences and Filaments on the Active Sun (2024-06-15)

This colorized and digitally sharpened image of the Sun is composed of frames recording emission from hydrogen atoms in the solar chromosphere on May 15. Approaching the maximum of solar cycle 25, a multitude of planet-dwarfing active regions and twisting, snake-like solar filaments are seen to sprawl across the surface of the active Sun.  Suspended in the active regions' strong magnetic fields, the filaments of plasma lofted beyond the Sun's edge appear as bright solar prominences. The large prominences seen near 4 o'clock, and just before 9 o'clock around the solar limb are post flare loops from two powerful X-class solar flares that both occurred on that day. In fact, the 4 o'clock prominence is associated with the monster active region AR 3664 just rotating off the Sun's edge.

Image credit: solar cycle 25
Animation: Black Hole Destroys Star (2024-06-16)

What happens if a star gets too close to a black hole? The black hole can rip it apart -- but how? It's not the high gravitational attraction itself that's the problem -- it's the difference in gravitational pull across the star that creates the destruction.  In the featured animated video illustrating this disintegration, you first see a star approaching the black hole.  Increasing in orbital speed, the star's outer atmosphere is ripped away during closest approach.  Much of the star's atmosphere disperses into deep space, but some continues to orbit the black hole and forms an accretion disk. The animation then takes you into the accretion disk while looking toward the black hole. Including the strange visual effects of gravitational lensing, you can even see the far side of the disk.  Finally, you look along one of the jets being expelled along the spin axis.  Theoretical models indicate that these jets not only expel energetic gas, but also create energetic neutrinos -- one of which may have been seen recently on Earth.    Almost Hyperspace: Random APOD Generator
Ou4: The Giant Squid Nebula (2024-06-17)

Squids on Earth aren't this big.  This mysterious squid-like cosmic cloud spans nearly three full moons on planet Earth's sky. Discovered in 2011 by French astro-imager Nicolas Outters, the Squid Nebula's bipolar shape is distinguished here by the telltale blue emission from doubly ionized oxygen atoms. Though apparently surrounded by the reddish hydrogen emission region Sh2-129, the true distance and nature of the Squid Nebula have been difficult to determine. Still, one investigation suggests Ou4 really does lie within Sh2-129 some 2,300 light-years away. Consistent with that scenario, the cosmic squid would represent a spectacular outflow of material driven by a triple system of hot, massive stars, cataloged as HR8119, seen near the center of the nebula. If so, this truly giant squid nebula would physically be over 50 light-years across.

Image credit: Alex Linde
Gigantic Jets over Himalayan Mountains (2024-06-18)

Yes, but can your thunderstorm do this? Pictured here are gigantic jets shooting up from a thunderstorm last week toward the Himalayan Mountains in China and Bhutan. The composite image captured four long jets that occurred only minutes apart. Gigantic jets, documented only in this century, are a type of lightning discharge that occurs between some thunderstorms and the Earth's ionosphere high above them.  They are an unusual type of lightning that is much different from regular cloud-to-cloud and cloud-to-ground lightning. The bottoms of gigantic jets appear similar to a  cloud-to-above strike called blue jets, while the tops appear similar to upper-atmosphere red sprites. Although the mechanism and trigger that cause gigantic jets remains a topic of research, it is clear that the jets reduce charge imbalance between different parts of Earth's atmosphere.  A good way to look for gigantic jets is to watch a powerful but distant thunderstorm from a clear location.

Image credit: Li Xuanhua
NGC 6188: Dragons of Ara (2024-06-19)

Do dragons fight on the altar of the sky?  Although it might appear that way, these dragons are illusions made of thin gas and dust. The emission nebula NGC 6188, home to the glowing clouds, is found about 4,000 light years away near the edge of a large molecular cloud, unseen at visible wavelengths, in the southern constellation Ara (the Altar). Massive, young stars of the embedded Ara OB1 association were formed in that region only a few million years ago, sculpting the dark shapes and powering the nebular glow with stellar winds and intense ultraviolet radiation. The recent star formation itself was likely triggered by winds and supernova explosions from previous generations of massive stars, that swept up and compressed the molecular gas. This impressively detailed image spans over 2 degrees (four full Moons), corresponding to over 150 light years at the estimated distance of NGC 6188.

Image credit: Carlos Taylor
Sandy and the Moon Halo (2024-06-20)

Last April's Full Moon shines through high clouds near the horizon, casting shadows in this garden-at-night skyscape. Along with canine sentinel Sandy watching the garden gate, the wide-angle snapshot also captured the bright Moon's 22 degree ice halo. But June's bright Full Moon will cast shadows too. This month, the Moon's exact full phase occurs at 01:08 UTC June 22. That's a mere 28 hours or so after today's June solstice (at 20:51 UTC June 20), the moment when the Sun reaches its maximum northern declination. Known to some as a Strawberry Moon, June's Full Moon is at its southernmost declination, and of course will create its own 22 degree halos in hazy night skies.

Image credit: Marcella Giulia Pace
Hubble's NGC 1546 (2024-06-21)

Returning to science operations on June 14, the Hubble Space Telescope used its new pointing mode to capture this sharp image of spiral galaxy NGC 1546. A member of the Dorado galaxy group, the island universe lies a mere 50 million light-years away. The galactic disk of NGC 1546 is tilted to our line-of-sight, with the yellowish light of the old stars and bluish regions of newly formed stars shining through the galaxy's dust lanes. More distant background galaxies are scattered throughout this Hubble view. Launched in 1990, Hubble has been exploring the cosmos for more than three decades, recently celebrating its 34th anniversary.
Lynds Dark Nebula 1251 (2024-06-22)

Stars are forming in Lynds Dark Nebula (LDN) 1251. About 1,000 light-years away and drifting above the plane of our Milky Way galaxy, LDN 1251 is also less appetizingly known as "The Rotten Fish Nebula." The dusty molecular cloud is part of a complex of dark nebulae mapped toward the Cepheus flare region. Across the spectrum, astronomical explorations of the obscuring interstellar clouds reveal energetic shocks and outflows associated with newborn stars, including the telltale reddish glow from scattered Herbig-Haro objects hiding in the image. Distant background galaxies also lurk in the scene, almost buried behind the dusty expanse. This alluring view spans over four full moons on the sky, or 35 light-years at the estimated distance of LDN 1251.

Image credit: Long Xin
The Colors of Saturn from Cassini (2024-06-23)

What creates Saturn's colors?  The featured picture of Saturn only slightly exaggerates what a human would see if hovering close to the giant ringed world.   The image was taken in 2005 by the robot Cassini spacecraft that orbited Saturn from 2004 to 2017.  Here Saturn's majestic rings appear directly only as a curved line, appearing brown, in part from its infrared glow.  The rings best show their complex structure in the dark shadows they create across the upper part of the planet.   The northern hemisphere of Saturn can appear partly blue for the same reason that Earth's skies can appear blue -- molecules in the cloudless portions of both planet's atmospheres are better at scattering blue light than red.  When looking deep into Saturn's clouds, however, the natural gold hue of Saturn's clouds becomes dominant.   It is not known why southern Saturn does not show the same blue hue -- one hypothesis holds that clouds are higher there.   It is also not known why some of Saturn's clouds are colored gold.
JADES-GS-z14-0: A New Farthest Object (2024-06-24)

What if we could see back to the beginning of the universe?  We could see galaxies forming.  But what did galaxies look like back then?  These questions took a step forward recently with the release of the analysis of a James Webb Space Telescope (JWST) image that included the most distant object yet discovered.  Most galaxies formed at about 3 billion years after the Big Bang, but some formed earlier. Pictured in the inset box is JADES-GS-z14-0, a faint smudge of a galaxy that formed only 300 million years after the universe started.  In technical terms, this galaxy lies at the record redshift of z=14.32, and so existed when the universe was only one fiftieth of the its present age.  Practically all of the objects in the featured photograph are galaxies.
The Dark Doodad Nebula (2024-06-25)

What is that strange brown ribbon on the sky?  When observing the star cluster NGC 4372, observers frequently take note of an unusual dark streak nearby running about three degrees in length. The streak, actually a long molecular cloud, has become known as the Dark Doodad Nebula.  (Doodad is slang for a thingy or a whatchamacallit.)  Pictured here, the Dark Doodad Nebula sweeps across the center of a rich and colorful starfield.  Its dark color comes from a high concentration of interstellar dust that preferentially scatters visible light.  The globular star cluster NGC 4372 is visible as the fuzzy white spot on the far left, while the bright blue star gamma Muscae is seen to the cluster's upper right. The Dark Doodad Nebula can be found with strong binoculars toward the southern constellation of the Fly (Musca).

Image credit: Martin Pugh &  
Rocco Sung
Timelapse: Aurora, SAR, and the Milky Way (2024-06-26)

What's happening in the sky this unusual night? Most striking in the featured 4.5-hour 360-degree panoramic video, perhaps, is the pink and purple aurora. That's because this night, encompassing May 11, was famous for its auroral skies around the world. As the night progresses, auroral bands shimmer, the central band of our Milky Way Galaxy rises, and stars shift as the Earth rotates beneath them.  Captured here simultaneously is a rare red band running above the aurora: a SAR arc, seen to change only slightly. The flashing below the horizon is caused by passing cars, while the moving spots in the sky are satellites and airplanes.  The featured video was captured from Xinjiang, China with four separate cameras.

Image credit: Jeff Dai
(TWAN); 
 Music: 
Ibaotu catalog number 771024
(Used with permission)
Protostellar Outflows in Serpens (2024-06-27)

Jets of material blasting from newborn stars, are captured in this James Webb Space Telescope close-up of the Serpens Nebula. The powerful protostellar outflows are bipolar, twin jets spewing in opposite directions. Their directions are perpendicular to accretion disks formed around the spinning, collapsing stellar infants. In the NIRcam image, the reddish color represents emission from molecular hydrogen and carbon monoxide produced as the jets collide with the surrounding gas and dust. The sharp image shows for the first time that individual outflows detected in the Serpens Nebula are generally aligned along the same direction. That result was expected, but has only now come into clear view with Webb's detailed exploration of the active young star-forming region. Brighter foreground stars exhibit Webb's characteristic diffraction spikes. At the Serpens Nebula's estimated distance of 1,300 light-years, this cosmic close-up frame is about 1 light-year across.
Comet 13P/Olbers (2024-06-28)

Not a paradox, Comet 13P/Olbers is returning to the inner Solar System after 68 years. The periodic, Halley-type comet will reach its next perihelion or closest approach to the Sun on June 30 and has become a target for binocular viewing low in planet Earth's northern hemisphere night skies. But this sharp telescopic image of 13P is composed of stacked exposures made on the night of June 25. It easily reveals shifting details in the bright comet's torn and tattered ion tail buffeted by the wind from an active Sun, along with a broad, fanned-out dust tail and slightly greenish coma. The frame spans over two degrees across a background of faint stars toward the constellation Lynx.

Image credit: Dan Bartlett
A Solstice Moon (2024-06-29)

Rising opposite the setting Sun, June's Full Moon occurred within about 28 hours of the solstice. The Moon stays close to the Sun's path along the ecliptic plane and so while the solstice Sun climbed high in daytime skies, June's Full Moon remained low that night as seen from northern latitudes. In fact, the Full Moon hugs the horizon in this June 21 rooftop night sky view from Bursa, Turkey, constructed from exposures made every 10 minutes between moonrise and moonset. In 2024 the Moon also reached a major lunar standstill, an extreme in the monthly north-south range of moonrise and moonset caused by the precession of the Moon's orbit over an 18.6 year cycle. As a result, this June solstice Full Moon was at its southernmost moonrise and moonset along the horizon.

Image credit: Tunc Tezel
Earthrise: A Video Reconstruction (2024-06-30)

About 12 seconds into this video, something unusual happens. The Earth begins to rise.  Never seen by humans before, the rise of the Earth over the limb of the Moon occurred about 55.5 years ago and surprised and amazed the crew of Apollo 8. The crew immediately scrambled to take still images of the stunning vista caused by Apollo 8's orbit around the Moon. The featured video is a modern reconstruction of the event as it would have looked were it recorded with a modern movie camera. The colorful orb of our Earth stood out as a familiar icon rising above a distant and unfamiliar moonscape, the whole scene the conceptual reverse of a more familiar moonrise as seen from Earth. To many, the scene also spoke about the unity of humanity: that big blue marble -- that's us -- we all live there. The two-minute video is not time-lapse -- this is the real speed of the Earth rising through the windows of Apollo 8. Seven months and three missions later, Apollo 11 astronauts would not only circle Earth's moon, but land on it.   NASA Administrator Remembers Earthrise Photographer William Anders
Time Spiral (2024-07-01)

What's happened since the universe started? The time spiral shown here features a few notable highlights. At the spiral's center is the Big Bang, the place where time, as we know it, began about 13.8 billion years ago. Within a few billion years atoms formed, then stars formed from atoms, galaxies formed from stars and gas, our Sun formed, soon followed by our Earth, about 4.6 billion years ago.  Life on Earth begins about 3.8 billion years ago, followed by cells, then photosynthesis within a billion years.  About 1.7 billion years ago, multicellular life on Earth began to flourish.  Fish began to swim about 500 million years ago, and mammals began walking on land about 200 million years ago. Humans first appeared only about 6 million years ago, and made the first cities only about 10,000 years ago.  The time spiral illustrated stops there, but human spaceflight might be added, which started only 75 years ago, and useful artificial intelligence began to take hold within only the past few years.   Explore Your Universe: Random APOD Generator
NGC 602: Oyster Star Cluster (2024-07-02)

The clouds may look like an oyster, and the stars like pearls, but look beyond. Near the outskirts of the Small Magellanic Cloud, a satellite galaxy some 200 thousand light-years distant, lies this 5 million year old star cluster NGC 602. Surrounded by its birth shell of gas and dust, star cluster NGC 602 is featured in this stunning Hubble image, augmented in a rollover by images in the X-ray by the Chandra Observatory and in the infrared by Spitzer Telescope. Fantastic ridges and swept back gas strongly suggest that energetic radiation and shock waves from NGC 602's massive young stars have eroded the dusty material and triggered a progression of star formation moving away from the star cluster's center. At the estimated distance of the Small Magellanic Cloud, the featured picture spans about 200 light-years, but a tantalizing assortment of background galaxies are also visible in this sharp view. The background galaxies are hundreds of millions of light-years -- or more -- beyond NGC 602.