juliensimon/nasa-apod huggingface dataset:
Messier 45: The Daughters of Atlas and Pleione (2023-01-05)

Hurtling through a cosmic dust cloud a mere 400 light-years away, the lovely Pleiades or Seven Sisters open star cluster is well-known for its striking blue reflection nebulae. It lies in the night sky toward the constellation Taurus and the Orion Arm of our Milky Way galaxy. The sister stars are not related to the dusty cloud though. They just happen to be passing through the same region of space. Known since antiquity as a compact grouping of stars, Galileo first sketched the star cluster viewed through his telescope with stars too faint to be seen by eye. Charles Messier recorded the position of the cluster as the 45th entry in his famous catalog of things which are not comets. In Greek myth, the Pleiades were seven daughters of the astronomical titan Atlas and sea-nymph Pleione. Their parents names are included in the cluster's nine brightest stars. This well-processed, color-calibrated telescopic image features pin-point stars and detailed filaments of interstellar dust captured in over 9 hours of exposure. It spans more than 20 light-years across the Pleiades star cluster.

Image credit: Stefan Thrun
Moon O'Clock 2022 (2023-01-06)

The first Full Moon of 2023 is in the sky tonight opposite the Sun at 23:08 UTC. Big and beautiful, the Moon at its brightest phase should be easy to spot. Still, for quick reference images captured near the times of all the full moons of 2022 are aranged in this dedicated astro-imaging project from Sri Lanka, planet Earth. The day, month, and a traditional popular name for 2022's twelve full moons are given in the chart. The apparent size of each full moon depends on how close the full lunar phase is to perigee or apogee, the closest or farthest point in the Moon's elliptical orbit. Like the 2022 Wolf Moon at the 1 o'clock position, tonight's Full Moon occurs within about two days of apogee. But unlike in 2022, the year 2023 will have 13 full moons that won't all fit nicely on the twelve hour clock.

Image credit: Niveth Kumar
Space Stations in Low Earth Orbit (2023-01-07)

On January 3, two space stations already illuminated by sunlight in low Earth orbit crossed this dark predawn sky. Moving west to east (left to right) across the composited timelapse image China's Tiangong Space Station traced the upper trail captured more than an hour before the local sunrise. Seen against a starry background Tiangong passes just below the inverted Big Dipper asterism of Ursa Major near the peak of its bright arc, and above north pole star Polaris. But less than five minutes before, the International Space Station had traced its own sunlit streak across the dark sky. Its trail begins just above the W-shape outlined by the bright stars of Cassiopeia near the northern horizon. The dramatic foreground spans an abandoned mine at Achada do Gamo in southeastern Portugal.

Image credit: Zarcos Palma
Where Your Elements Came From (2023-01-08)

The hydrogen in your body, present in every molecule of water, came from the Big Bang.  There are no other appreciable sources of hydrogen in the universe.  The carbon in your body was made by nuclear fusion in the interior of stars, as was the oxygen.  Much of the iron in your body was made during supernovas of stars that occurred long ago and far away.  The gold in your jewelry was likely made from neutron stars during collisions that may have been visible as short-duration gamma-ray bursts or gravitational wave events. Elements like phosphorus and copper are present in our bodies in only small amounts but are essential to the functioning of all known life.  The featured periodic table is color coded to indicate humanity's best guess as to the nuclear origin of all known elements.  The sites of nuclear creation of some elements, such as copper, are not really well known and are continuing topics of observational and computational research.   Discovery + Outreach: Graduate student research position open for APOD
Tails of Comet ZTF (2023-01-09)

Comet ZTF may become visible to the unaided eye. Discovered early last year, this massive snowball has been brightening as it approaches the Sun and the Earth. C/2022 E3 (ZTF) will be closest to the Sun later this week, at which time it may become visible even without binoculars to northern observers with a clear and dark sky. As they near the Sun, comet brightnesses are notoriously hard to predict, though. In the featured image taken last week in front of a picturesque star field, three blue ion tails extend to the upper right, likely the result of a variable solar wind on ions ejected by the icy comet nucleus.  The comet's white dust tail is visible to the upper left and much shorter. The green glow is the comet's coma, caused by glowing carbon gas. Comet ZTF is expected to pass nearest the Earth in early February, after which it should dim dramatically.   Discovery + Outreach: Graduate student research position open for APOD

Image credit: Jose Francisco Hernández
NGC 2264: The Cone Nebula (2023-01-10)

Stars are forming in the gigantic dust pillar called the Cone Nebula. Cones, pillars, and majestic flowing shapes abound in stellar nurseries where clouds of gas and dust are sculpted by energetic winds from newborn stars. The Cone Nebula, a well-known example, lies within the bright galactic star-forming region NGC 2264. The featured image of the Cone was captured recently combining 24-hours of exposure with a half-meter telescope at the El Sauce Observatory in Chile. Located about 2,500 light-years away toward the constellation of the Unicorn (Monoceros), the Cone Nebula's conical pillar extends about 7 light-years. The massive star NGC 2264 IRS, is the likely source of the wind sculpting the Cone Nebula and lies off the top of the image.  The Cone Nebula's reddish veil is produced by glowing hydrogen gas.    Discovery + Outreach: Graduate student research position open for APOD

Image credit: Matthew Dieterich
Spiral Aurora over Iceland (2023-01-11)

The scene may look like a fantasy, but it's really Iceland. The rock arch is named Gatklettur and located on the island's northwest coast. Some of the larger rocks in the foreground span a meter across. The fog over the rocks is really moving waves averaged over long exposures.  The featured image is a composite of several foreground and background shots taken with the same camera and from the same location on the same night last November.  The location was picked for its picturesque foreground, but the timing was planned for its colorful background: aurora. The spiral aurora, far behind the arch, was one of the brightest seen in the astrophotographer's life.  The coiled pattern was fleeting, though, as auroral patterns waved and danced for hours during the cold night.  Far in the background were the unchanging stars, with Earth's rotation causing them to appear to slowly circle the sky's northernmost point near Polaris.    Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

Image credit: Stefano Pellegrini
Stardust in Perseus (2023-01-12)

This cosmic expanse of dust, gas, and stars covers some 6 degrees on the sky in the heroic constellation Perseus. At upper left in the gorgeous skyscape is the intriguing young star cluster IC 348 and neighboring Flying Ghost Nebula with clouds of obscuring interstellar dust cataloged as Barnard 3 and 4. At right, another active star forming region NGC 1333 is connected by dark and dusty tendrils on the outskirts of the giant Perseus Molecular Cloud, about 850 light-years away. Other dusty nebulae are scattered around the field of view, along with the faint reddish glow of hydrogen gas. In fact, the cosmic dust tends to hide the newly formed stars and young stellar objects or protostars from prying optical telescopes. Collapsing due to self-gravity, the protostars form from the dense cores embedded in the molecular cloud. At the molecular cloud's estimated distance, this field of view would span over 90 light-years.

Image credit: Jack Groves
Young Star Cluster NGC 346 (2023-01-13)

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.
Perihelion Sun 2023 (2023-01-14)

Perihelion for 2023, Earth's closest approach to the Sun, was on January 4 at 16:17 UTC. That was less than 24 hours after this sharp image of the Sun's disk was recorded with telescope and H-alpha filter from Sydney, Australia, planet Earth.  An H-alpha filter transmits a characteristic red light from hydrogen atoms. In views of the Sun it emphasizes the Sun's chromosphere, a region just above the solar photosphere or normally visible solar surface. In this H-alpha image of the increasingly active Sun planet-sized sunspot regions are dominated by bright splotches called plages. Dark filaments of plasma snaking across the solar disk transition to bright prominences when seen above the solar limb.

Image credit: Barden Ridge Observatory
M1: The Crab Nebula from Hubble (2023-01-15)

This is the mess that is left when a star explodes.  The Crab Nebula, the result of a supernova seen in 1054 AD, is filled with mysterious filaments.  The filaments are not only tremendously complex, but appear to have less mass than expelled in the original supernova and a higher speed than expected from a free explosion.  The featured image, taken by the Hubble Space Telescope, is presented in three colors chosen for scientific interest.  The Crab Nebula spans about 10 light-years.  In the nebula's very center lies a pulsar: a neutron star as massive as the Sun but with only the size of a small town.  The Crab Pulsar rotates about 30 times each second.   Discovery + Outreach: Graduate student research position open for APOD
Moon Enhanced (2023-01-16)

Our Moon doesn't really look like this.  Earth's Moon, Luna, doesn't naturally show this rich texture, and its colors are more subtle. But this digital creation is based on reality.  The featured image is a composite of multiple images and enhanced to bring up real surface features.  The enhancements, for example, show more clearly craters that illustrate the tremendous bombardment our Moon has been through during its 4.6-billion-year history.  The dark areas, called maria, have fewer craters and were once seas of molten lava. Additionally, the image colors, although based on the moon's real composition, are changed and exaggerated.  Here, a blue hue indicates a region that is iron rich, while orange indicates a slight excess of aluminum.  Although the Moon has shown the same side to the Earth for billions of years, modern technology is allowing humanity to learn much more about it -- and how it affects the Earth.

Image credit: Darya Kawa Mirza
Unexpected Clouds Toward the Andromeda Galaxy (2023-01-17)

Why are there oxygen-emitting arcs near the direction of the Andromeda galaxy? No one is sure. The gas arcs, shown in blue, were discovered and first confirmed by amateur astronomers just last year. The two main origin hypotheses for the arcs are that they really are close to Andromeda (M31), or that they are just coincidentally placed gas filaments in our Milky Way galaxy.  Adding to the mystery is that arcs were not seen in previous deep images of M31 taken primarily in light emitted by hydrogen, and that other, more distant galaxies have not been generally noted as showing similar oxygen-emitting structures.  Dedicated amateurs using commercial telescopes made this discovery because, in part, professional telescopes usually investigate angularly small patches of the night sky, whereas these arcs span several times the angular size of the full moon.  Future observations -- both in light emitted by oxygen and by other elements -- are sure to follow.

Image credit: Yann Sainty & 
Marcel Drechsler
MACS0647: Gravitational Lensing of the Early Universe by Webb (2023-01-18)

Gravitational lensing by the galaxy cluster MACS0647 -- in which the massive foreground cluster distorts and lenses the light emitted by distant background galaxies along the line of sight — is on vivid display here in this recent multi-color infrared image from the James Webb Space Telescope (JWST).  In particular, the background source MACS0647-JD is seen to be lensed three times by the cluster.  When first discovered with the Hubble Space Telescope, MACS0647-JD was observed as an amorphous blob.  With Webb though, this single source is revealed to be a pair or small group of galaxies.  The colors of the MACS0647-JD objects are different as well -- indicating differences potentially in the age or dust content of these galaxies.  These new images provide rare examples of galaxies in an era only a few 100 million years after the Big Bang.   Explore Your Universe: Random APOD Generator
The Seagull Nebula (2023-01-19)

A broad expanse of glowing gas and dust presents a bird-like visage to astronomers from planet Earth, suggesting its popular moniker - The Seagull Nebula. Using narrowband image data, this 3-panel mosaic of the cosmic bird covers a 2.5 degree swath across the plane of the Milky Way, near the direction of Sirius, alpha star of the constellation Canis Major. Likely part of a larger shell structure swept up by successive supernova explosions, the broad Seagull Nebula is cataloged as Sh2-296 and IC 2177. The prominent bluish arc below and right of center is a bow shock from runaway star FN Canis Majoris. This complex of gas and dust clouds with other stars of the Canis Majoris OB1 association spans over 200 light-years at the Seagull Nebula's estimated 3,800 light-year distance.

Image credit: Carlos Taylor
Galaxy Wars: M81 and M82 (2023-01-20)

The two dominant galaxies near center are far far away, 12 million light-years distant toward the northern constellation of the Great Bear. On the right, with grand spiral arms and bright yellow core is spiral galaxy M81. Also known as Bode's galaxy, M81 spans some 100,000 light-years. On the left is cigar-shaped irregular galaxy M82.  The pair have been locked in gravitational combat for a billion years. Gravity from each galaxy has profoundly affected the other during a series of cosmic close encounters.  Their last go-round lasted about 100 million years and likely raised density waves rippling around M81, resulting in the richness of M81's spiral arms.  M82 was left with violent star forming regions and colliding gas clouds so energetic that the galaxy glows in X-rays.  In the next few billion years, their continuing gravitational encounters will result in a merger, and a single galaxy will remain. This extragalactic scenario also includes other members of the interacting M81 galaxy group with NGC 3077 below and right of the large spiral, and NGC 2976 at upper right in the frame. Captured under dark night skies in the Austrian Alps, the foreground of the wide-field image is filled with integrated flux nebulae. Those faint, dusty interstellar clouds reflect starlight above the plane of our own Milky Way galaxy.

Image credit: Andreas Aufschnaiter
Naked-eye Comet ZTF (2023-01-21)

Comet C/2022E3 (ZTF) no longer requires a telescope for viewing. By January 19, it could just be seen with the naked eye in this rural sky with little light pollution from a location about 20 kilometers from Salamanca, Spain. Still, telescopic images are needed to show any hint of the comet's pretty green coma, stubby whitish dust tail, and long ion tail. Its faint ion tail has been buffeted by recent solar activity. This visitor from the distant Oort cloud rounded the Sun on January 12. and is now sweeping through stars near the northern boundary of the constellation Bootes. Outward bound but still growing brighter, Comet ZTF makes its closest approach on February 2, coming to within about 2.4 light-minutes of our fair planet.

Image credit: Organización Salmantina de la Astronáutica y el Espacio
In Green Company: Aurora over Norway (2023-01-22)

Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds -- mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display. Arms went high in the air, patience and experience paid off, and the creative featured image was captured as a composite from three separate exposures. The setting is a summit of the Austnesfjorden fjord close to the town of Svolvear on the Lofoten islands in northern Norway. The time was early 2014. Although our Sun passed the solar minimum of its 11-year cycle only a few years ago, surface activity is picking up and already triggering more spectacular auroras here on Earth.

Image credit: Max Rive
The Colliding Spiral Galaxies of Arp 274 (2023-01-23)

Two galaxies are squaring off in Virgo and here are the latest pictures.  When two galaxies collide, the stars that compose them usually do not. This is because galaxies are mostly empty space and, however bright, stars only take up only a small fraction of that space. But during the collision, one galaxy can rip the other apart gravitationally, and dust and gas common to both galaxies does collide. If the two galaxies merge, black holes that likely resided in each galaxy center may eventually merge. Because the distances are so large, the whole thing takes place in slow motion -- over hundreds of millions of years. Besides the two large spiral galaxies, a smaller third galaxy is visible on the far left of the featured image of Arp 274, also known as NGC 5679. Arp 274 spans about 200,000 light years across and lies about 400 million light years away toward the constellation of Virgo.   Night Sky Network webinar: APOD editor to review best space images of 2022
LHS 475 b: Earth-Sized Exoplanet (2023-01-24)

If you could stand on exoplanet LHS 475 b, what might you see? No one knows for sure but pictured here is an interesting guess made by an Earth-based artificial intelligence (AI) engine. The existence of the exoplanet was indicated in data taken by the Earth-orbiting TESS satellite but confirmed and further investigated only this year by the near-Earth Sun-orbiting James Webb Space Telescope. What is known for sure is that LHS 475 b has a mass very similar to our Earth and closely orbits a small red star about 40 light years away. The featured AI-illustrated guess depicts a plausibly rugged Earth-like landscape replete with molten lava and with the central red star rising in the distance. Webb data does not as yet reveal, however, whether LHS 475 b has an atmosphere. One of Webb’s science objectives is to follow up previous discoveries of distant exoplanets to better discern their potential for developing life.    Comet ZTF Gallery: Notable Submissions to APOD
LDN 1622: The Boogeyman Nebula (2023-01-25)

To some, the dark shape looks like a mythical boogeyman.  Scientifically, Lynds' Dark Nebula (LDN) 1622 appears against a faint background of glowing hydrogen gas only visible in long telescopic exposures of the region. In contrast, the brighter reflection nebula vdB 62 is more easily seen just above and to the right of center in the featured image. LDN 1622 lies near the plane of our Milky Way Galaxy, close on the sky to Barnard's Loop, a large cloud surrounding the rich complex of emission nebulae found in the Belt and Sword of Orion. With swept-back outlines, the obscuring dust of LDN 1622 is thought to lie at a similar distance, perhaps 1,500 light-years away. At that distance, this 2-degree wide field of view would span about 60 light-years. Young stars do lie hidden within the dark expanse and have been revealed in Spitzer Space Telescope infrared images.

Image credit: Joshua Carter
Active Galaxy NGC 1275 (2023-01-26)

Active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies. Wild-looking at visible wavelengths, the active galaxy is also a prodigious source of x-rays and radio emission. NGC 1275 accretes matter as entire galaxies fall into it, ultimately feeding a supermassive black hole at the galaxy's core. This color composite image made from Hubble Space Telescope data recorded during 2006. It highlights the resulting galactic debris and filaments of glowing gas, some up to 20,000 light-years long. The filaments persist in NGC 1275, even though the turmoil of galactic collisions should destroy them.  What keeps the filaments together? Observations indicate that the structures, pushed out from the galaxy's center by the black hole's activity, are held together by magnetic fields. Also known as Perseus A, NGC 1275 spans over 100,000 light years and lies about 230 million light years away.
Comet ZTF: Orbital Plane Crossing (2023-01-27)

The current darling of the northern night, Comet C/2022 E3 ZTF is captured in this telescopic image from a dark sky location at June Lake, California, USA. Of course Comet ZTF has been growing brighter in recent days, headed for its closest approach to Earth on February 1.  But this view was recorded on January 23, very close to the time planet Earth crossed the orbital plane of long-period Comet ZTF. The comet's broad, whitish dust tail is still curved and fanned out away from the Sun as Comet ZTF sweeps along its orbit. Due to perspective near the orbital plane crossing, components of the fanned out dust tail appear on both sides of the comet's green tinted coma though, to lend Comet ZTF a visually striking (left) anti-tail. Buffeted by solar activity the comet's narrower ion tail also streams away from the coma diagonally to the right, across the nearly three degree wide field of view.   Comet ZTF Gallery: Notable Submissions to APOD

Image credit: Dan Bartlett
Comet ZTF over Mount Etna (2023-01-28)

Comet-like plumes are blowing over the volcanic peaks of Mount Etna in this wintry mountain-and-skyscape from planet Earth. The stacked and blended combination of individual exposures recorded during the cold night of January 23, also capture naked-eye Comet ZTF just above Etna's snowy slopes. Of course the effect of increasing sunlight on the comet's nucleus and the solar wind are responsible for the comet's greenish coma and broad dusty tail. This weekend Comet ZTF is dashing across northern skies between north star Polaris and the Big Dipper. From a dark site you can only just spot it as a fuzzy patch though. That's still an impressive achievement if you consider you are gazing at a visitor from the distant Oort cloud with your own eyes. But binoculars or a small telescope will make for an even more enjoyable view of this Comet ZTF in the coming days.   Comet ZTF Gallery: Notable Submissions to APOD

Image credit: Dario Giannobile