juliensimon/nasa-apod huggingface dataset:
Tycho and Clavius at Dawn (2022-07-16)

South is up in this dramatic telescopic view of the lunar terminator and the Moon's rugged southern highlands. The lunar landscape was captured on July 7 with the moon at its first quarter phase. The Sun shines at a low angle from the right as dawn comes to the region's young and old craters Tycho and Clavius. About 100 million years young, Tycho is the sharp-walled 85 kilometer diameter crater below and left of center. Its 2 kilometer tall central peak and far crater wall reflect bright sunlight, Its smooth floor lies in dark shadow. Debris ejected during the impact that created Tycho make it the stand out lunar crater when the Moon is near full though. They produce a highly visible radiating system of light streaks or rays that extend across much of the lunar near side. In fact, some of the material collected at the Apollo 17 landing site, about 2,000 kilometers away, likely originated from the Tycho impact.  One of the oldest and largest craters on the Moon's near side, 225 kilometer diameter Clavius is due south (above) of Tycho. Clavius crater's own ray system resulting from its original impact event would have faded long ago. The old crater's worn walls and smooth floor are now overlayed by newer smaller craters from impacts that occurred after Clavius was formed. Reaching above the older crater, tops of the newer crater walls reflect this dawn's early light to create narrow shining arcs within a shadowed Clavius.

Image credit: Eduardo
Schaberger Poupeau
Europa and Jupiter from Voyager 1 (2022-07-17)

What are those spots on Jupiter? Largest and furthest, just right of center, is the Great Red Spot -- a huge storm system that has been raging on Jupiter possibly since Giovanni Cassini's likely notation of it 357 years ago.  It is not yet known why this Great Spot is red. The spot toward the lower left is one of Jupiter's largest moons: Europa. Images from Voyager in 1979 bolster the modern hypothesis that Europa has an underground ocean and is therefore a good place to look for extraterrestrial life. But what about the dark spot on the upper right? That is a shadow of another of Jupiter's large moons: Io. Voyager 1 discovered Io to be so volcanic that no impact craters could be found.  Sixteen frames from Voyager 1's flyby of Jupiter in 1979 were recently reprocessed and merged to create the featured image.  Forty-five years ago this September, Voyager 1 launched from Earth and started one of the greatest explorations of the Solar System ever.    Free Download: Voyager Posters
Stephan's Quintet from Webb, Hubble, and Subaru (2022-07-18)

OK, but why can't you combine images from Webb and Hubble? You can, and today's featured image shows one impressive result. Although the recently launched James Webb Space Telescope (Webb) has a larger mirror than Hubble, it specializes in infrared light and can't see blue -- only up to about orange.  Conversely, the Hubble Space Telescope (Hubble) has a smaller mirror than Webb and can't see as far into the infrared as Webb, but can image not only blue light but even ultraviolet.  Therefore, Webb and Hubble data can be combined to create images across a wider variety of colors.  The featured image of four galaxies from Stephan's Quintet shows Webb images as red and also includes images taken by Japan's ground-based Subaru telescope in Hawaii.  Because image data for Webb, Hubble, and Subaru are made freely available, anyone around the world can process it themselves, and even create intriguing and scientifically useful multi-observatory montages.    Stephan's Quintet from just: Webb, Hubble
Pleiades over Half Dome (2022-07-19)

Stars come in bunches.  The most famous bunch of stars on the sky is the Pleiades, a bright cluster that can be easily seen with the unaided eye.  The Pleiades lies only about 450 light years away, formed about 100 million years ago, and will likely last about another 250 million years. Our Sun was likely born in a star cluster, but now, being about 4.5 billion years old, its stellar birth companions have long since dispersed. The Pleiades star cluster is pictured over Half Dome, a famous rock structure in Yosemite National Park in California, USA. The featured image is a composite of 28 foreground exposures and 174 images of the stellar background, all taken from the same location and by the same camera on the same night in October 2019. After calculating the timing of a future juxtaposition of the Pleiades and Half Dome, the astrophotrographer was unexpectedly rewarded by an electrical blackout, making the background sky unusually dark.

Image credit: Dheera Venkatraman
Jupiter and Ring in Infrared from Webb (2022-07-20)

Why does Jupiter have rings?  Jupiter's main ring was discovered in 1979 by NASA's passing Voyager 1 spacecraft, but its origin was then a mystery.  Data from NASA's Galileo spacecraft that orbited Jupiter from 1995 to 2003, however, confirmed the hypothesis that this ring was created by meteoroid impacts on small nearby moons.  As a small meteoroid strikes tiny Metis, for example, it will bore into the moon, vaporize, and explode dirt and dust off into a Jovian orbit. The featured image of Jupiter in infrared light by the James Webb Space Telescope shows not only Jupiter and its clouds, but this ring as well. Also visible is Jupiter's Great Red Spot (GRS) -- in comparatively light color on the right, Jupiter's large moon Europa -- in the center of diffraction spikes on the left, and Europa's shadow -- next to the GRS.  Several features in the image are not yet well understood, including the seemingly separated cloud layer on Jupiter's right limb.    Celestial Surprise: What picture did APOD feature on your birthday? (post 1995)
Messier 10 and Comet (2022-07-21)

Imaged on July 15 2022, comet C/2017 K2 (PanSTARRS) had a Messier moment, sharing this wide telescopic field of view with globular star cluster Messier 10. Of course M10 was cataloged by 18th century comet hunter Charles Messier as the 10th object on his list of things that were definitely not comets. While M10 is about 14 thousand light-years distant, this comet PanSTARRS was about 15 light-minutes from our fair planet following its July 14 closest approach. Its greenish coma and dust tail entertaining 21st century comet watchers, C/2017 K2 is expected to remain a fine telescopic comet in northern summer skies. On a maiden voyage from our Solar System's remote Oort Cloud this comet PanSTARRS was discovered in May 2017 when it was beyond the orbit of Saturn. At the time that made it the most distant active inbound comet known. Its closest approach to the Sun will be within 1.8 astronomical units on December 19, beyond the orbital distance of Mars.

Image credit: German Penelas Perez
Spiral Galaxy M74: A Sharper View (2022-07-22)

Beautiful spiral galaxy Messier 74 (also known as NGC 628) lies some 32 million light-years away toward the constellation Pisces. An island universe of about 100 billion stars with two prominent spiral arms, M74 has long been admired by astronomers as a perfect example of a grand-design spiral galaxy. M74's central region is brought into a stunning, sharp focus in this recently processed image using publicly available data from the James Webb Space Telescope. The colorized combination of image data sets is from two of Webb's instruments NIRcam and MIRI, operating at near- and mid-infrared wavelengths.  It reveals cooler stars and dusty structures in the grand-design spiral galaxy only hinted at in previous space-based views.

Image credit: Robert Eder
Apollo 11 Landing Panorama (2022-07-23)

Have you seen a panorama from another world lately?  Assembled from high-resolution scans of the original film frames, this one sweeps across the magnificent desolation of the Apollo 11 landing site on the Moon's Sea of Tranquility. The images were taken by Neil Armstrong looking out his window of the Eagle Lunar Module shortly after the July 20, 1969 landing. The frame at the far left (AS11-37-5449) is the first picture taken by a person on another world. Toward the south, thruster nozzles can be seen in the foreground on the left, while at the right, the shadow of the Eagle is visible to the west. For scale, the large, shallow crater on the right has a diameter of about 12 meters. Frames taken from the Lunar Module windows about an hour and a half after landing, before walking on the lunar surface, were intended to initially document the landing site in case an early departure was necessary.
Saturn in Infrared from Cassini (2022-07-24)

Many details of Saturn appear clearly in infrared light.  Bands of clouds show great structure, including long stretching storms.  Also quite striking in infrared is the unusual hexagonal cloud pattern surrounding Saturn's North Pole.  Each side of the dark hexagon spans roughly the width of our Earth. The hexagon's existence was not predicted, and its origin and likely stability remains a topic of research.  Saturn's famous rings circle the planet and cast shadows below the equator. The featured image was taken by the robotic Cassini spacecraft in 2014 in several infrared colors.  In 2017 September, the Cassini mission was brought to a dramatic conclusion when the spacecraft was  directed to dive into ringed giant.    Explore Your Universe: Random APOD Generator
Find the New Moon (2022-07-25)

Can you find the Moon? This usually simple task can be quite difficult.  Even though the Moon is above your horizon half of the time, its phase can be anything from crescent to full. The featured image was taken in late May from Sant Martí d'Empúries, Spain, over the Mediterranean Sea in the early morning. One reason you can't find this moon is because it is very near to its new phase, when very little of the half illuminated by the Sun is visible to the Earth. Another reason is because this moon is near the horizon and so seen through a long path of Earth's atmosphere -- a path which dims the already faint crescent. Any crescent moon is only visible near the direction the Sun, and so only locatable near sunrise or sunset. The Moon runs through all of its phases in a month (moon-th), and this month the thinnest sliver of a crescent -- a new moon -- will occur in three days.

Image credit: Mohamad Soltanolkotabi
Comet NEOWISE Rising over the Adriatic Sea (2022-07-26)

This sight was worth getting out of bed early.  Two years ago this month, Comet C/2020 F3 (NEOWISE) rose before dawn to the delight of northern sky enthusiasts awake that early. Up before sunrise on July 8th, the featured photographer was able to capture in dramatic fashion one of the few comets visible to the unaided eye this century, an inner-Solar System intruder that has become known as the Great Comet of 2020.  The resulting video detailed Comet NEOWISE from Italy rising over the Adriatic Sea. The time-lapse video combines over 240 images taken over 30 minutes.  The comet was seen rising through a foreground of bright and undulating noctilucent clouds, and before a background of distant stars.  Comet NEOWISE remained unexpectedly bright until 2020 August, with its ion and dust tails found to emanate from a nucleus spanning about five kilometers across.    Astrophysicists: Browse 2,800+ codes in the Astrophysics Source Code Library

Image credit: Paolo Girotti
Crepuscular Moon Rays over Denmark (2022-07-27)

This moon made quite an entrance. Typically, a moonrise is quiet and serene.  Taking a few minutes to fully peek above the horizon, Earth's largest orbital companion can remain relatively obscure until it rises high in the nighttime sky. About a week ago, however, and despite being only half lit by the Sun, this rising moon put on a show -- at least from this location. The reason was that, as seen from Limfjord in Nykøbing Mors, Denmark, the moon rose below scattered clouds near the horizon.  The result, captured here in a single exposure, was that moonlight poured through gaps in the clouds to created what are called crepuscular rays.  These rays can fan out dramatically across the sky when starting near the horizon, and can even appear to converge on the other side of the sky. Well behind our Moon, stars from our Milky Way galaxy dot the background, and our galaxy's largest orbital companion -- the Andromeda galaxy -- can be found on the upper left.    Almost Hyperspace: Random APOD Generator

Image credit: Ruslan Merzlyakov 
(astrorms)
North Celestial Tree (2022-07-28)

An ancient tree seems to reach out and touch Earth's North Celestial Pole in this well-planned night skyscape. Consecutive exposures for the timelapse composition were recorded with a camera fixed to a tripod in the Yiwu Desert Poplar Forests in northwest Xinjiang, China. The graceful star trail arcs reflect Earth's daily rotation around its axis. By extension, the axis of rotation leads to the center of the concentric arcs in the night sky. Known as the North Star, bright star Polaris is a friend to northern hemisphere night sky photographers and celestial navigators alike. That's because Polaris lies very close to the North Celestial Pole on the sky. Of course it can be found at the tip of an outstretched barren branch in a postcard from a rotating planet.

Image credit: Jeff Dai
SOFIA's Southern Lights (2022-07-29)

SOFIA, the Stratospheric Observatory for Infrared Astronomy, is a Boeing 747SP aircraft modified to carry a large reflecting telescope into the stratosphere. The ability of the airborne facility to climb above about 99 percent of Earth's infrared-blocking atmosphere has allowed researchers to observe from almost anywhere over the planet. On a science mission flying deep into the southern auroral oval, astronomer Ian Griffin, director of New Zealand’s Otago Museum, captured this view from the observatory's south facing starboard side on July 17. Bright star Canopus shines in the southern night above curtains of aurora australis, or southern lights. The plane was flying far south of New Zealand at the time at roughly 62 degrees southern latitude. Unfortunately, after a landing at Christchurch severe weather damaged SOFIA requiring repairs and the cancellation of the remainder of its final southern hemisphere deployment.

Image credit: Ian Griffin
The Eagle Rises (2022-07-30)

Get out your red/blue glasses and check out this stereo view from lunar orbit. The 3D anaglyph was created from two photographs (AS11-44-6633, AS11-44-6634) taken by astronaut Michael Collins during the 1969 Apollo 11 mission. It features the lunar module ascent stage, dubbed The Eagle, rising to meet the command module in lunar orbit on July 21. Aboard the ascent stage are Neil Armstrong and Buzz Aldrin, the first to walk on the Moon. The smooth, dark area on the lunar surface is Mare Smythii located just below the equator on the extreme eastern edge of the Moon's near side.  Poised beyond the lunar horizon is our fair planet Earth.

Image credit: ALSJ
Starburst Galaxy M94 from Hubble (2022-07-31)

Why does this galaxy have a ring of bright blue stars?  Beautiful island universe Messier 94 lies a mere 15 million light-years distant in the northern constellation of the Hunting Dogs (Canes Venatici). A popular target for Earth-based astronomers, the face-on spiral galaxy is about 30,000 light-years across, with spiral arms sweeping through the outskirts of its broad disk. But this Hubble Space Telescope field of view spans about 7,000 light-years across M94's central region. The featured close-up highlights the galaxy's compact, bright nucleus, prominent inner dust lanes, and the remarkable bluish ring of young massive stars. The ring stars are all likely less than 10 million years old, indicating that M94 is a starburst galaxy that is experiencing an epoch of rapid star formation from inspiraling gas. The circular ripple of blue stars is likely a wave propagating outward, having been triggered by the gravity and rotation of a oval matter distributions. Because M94 is relatively nearby, astronomers can better explore details of its starburst ring.
Mountains of Dust in the Carina Nebula (2022-08-01)

It's stars versus dust in the Carina Nebula and the stars are winning. More precisely, the energetic light and winds from massive newly formed stars are evaporating and dispersing the dusty stellar nurseries in which they formed. Located in the Carina Nebula and known informally as Mystic Mountain, these pillar's appearance is dominated by the dark dust even though it is composed mostly of clear hydrogen gas. Dust pillars such as these are actually much thinner than air and only appear as mountains due to relatively small amounts of opaque interstellar dust.  About 7,500 light-years distant, the featured image was taken with the Hubble Space Telescope and highlights an interior region of Carina which spans about three light years. Within a few million years, the stars will likely win out completely and the entire dust mountain will evaporate.
A Moon Dressed Like Saturn (2022-08-02)

Why does Saturn appear so big? It doesn't -- what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow. The Sun directly illuminates the brightly lit lunar crescent from the bottom, which means that the Sun must be below the horizon and so the image was taken before sunrise.  This double take-inducing picture was captured on 2019 December 24, two days before the Moon slid in front of the Sun to create a solar eclipse. In the foreground, lights from small Guatemalan towns are visible behind the huge volcano Pacaya.    News: APOD Receives First Outreach Prize from the International Astronomical Union

Image credit: Francisco Sojuel
Halo of the Cat's Eye (2022-08-03)

What created the unusual halo around the Cat's Eye nebula? No one is sure. What is sure is that the Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae on the sky.  Although haunting symmetries are seen in the bright central region, this image was taken to feature its intricately structured outer halo, which spans over three light-years across.  Planetary nebulae have long been appreciated as a final phase in the life of a Sun-like star. Only recently however, have some planetaries been found to have expansive halos, likely formed from material shrugged off during earlier puzzling episodes in the star's evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the age of the outer filamentary portions of the Cat's Eye Nebula's halo to be 50,000 to 90,000 years.

Image credit: Bray Falls
M13: The Great Globular Cluster in Hercules (2022-08-04)

In 1716, English astronomer Edmond Halley noted, "This is but a little Patch, but it shows itself to the naked Eye, when the Sky is serene and the Moon absent." Of course, M13 is now less modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the northern sky. Sharp telescopic views like this one reveal the spectacular cluster's hundreds of thousands of stars. At a distance of 25,000 light-years, the cluster stars crowd into a region 150 light-years in diameter. Approaching the cluster core upwards of 100 stars could be contained in a cube just 3 light-years on a side. For comparison, the closest star to the Sun is over 4 light-years away. The remarkable range of brightness recorded in this image follows stars into the dense cluster core. Distant background galaxies in the medium-wide field of view include NGC 6207 at the upper left.

Image credit: Joan Josep Isach Cogollos
A Beautiful Trifid (2022-08-05)

The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid does illustrate three different types of astronomical nebulae; red emission nebulae dominated by light from hydrogen atoms, blue reflection nebulae produced by dust reflecting starlight, and dark nebulae where dense dust clouds appear in silhouette. But the red emission region, roughly separated into three parts by obscuring dust lanes, is what lends the Trifid its popular name. Pillars and jets sculpted by newborn stars, above and right of the emission nebula's center, appear in famous Hubble Space Telescope close-up images of the region. The Trifid Nebula is about 40 light-years across. Too faint to be seen by the unaided eye, it almost covers the area of a full moon in planet Earth's sky. Open star cluster M21 just peeks into this telescopic field of view along the bottom right edge of the frame.

Image credit: Vikas Chander
Stereo Phobos (2022-08-06)

Get out your red/blue glasses and float next to Phobos, grooved moon of Mars! Captured in 2004 by the High Resolution Stereo Camera on board ESA's Mars Express spacecraft, the image data was recorded at a distance of about 200 kilometers from the martian moon. This tantalizing stereo anaglyph view shows the Mars-facing side of Phobos. It highlights the asteroid-like moon's cratered and grooved surface. Up to hundreds of meters wide, the mysterious grooves may be related to the impact that created Stickney crater, the large crater at the left. Stickney crater is about 10 kilometers across, while Phobos itself is only around 27 kilometers across at its widest point.
Meteor before Galaxy (2022-08-07)

What's that green streak in front of the Andromeda galaxy? A meteor. While photographing the Andromeda galaxy in 2016, near the peak of the Perseid Meteor Shower, a small pebble from deep space crossed right in front of our Milky Way Galaxy's far-distant companion. The small meteor took only a fraction of a second to pass through this 10-degree field.  The meteor flared several times while braking violently upon entering Earth's atmosphere.  The green color was created, at least in part, by the meteor's gas glowing as it vaporized. Although the exposure was timed to catch a Perseid meteor, the orientation of the imaged streak seems a better match to a meteor from the Southern Delta Aquariids, a meteor shower that peaked a few weeks earlier.  Not coincidentally, the Perseid Meteor Shower peaks later this week, although this year the meteors will have to outshine a sky brightened by a nearly full moon.

Image credit: Fritz
Helmut Hemmerich
The Lagoon Nebula without Stars (2022-08-08)

Ridges of glowing interstellar gas and dark dust clouds inhabit the turbulent, cosmic depths of the Lagoon Nebula. Also known as M8, the bright star forming region is about 5,000 light-years distant. But it still makes for a popular stop on telescopic tours of the constellation Sagittarius, toward the center of our Milky Way Galaxy. Dominated by the telltale red emission of ionized hydrogen atoms recombining with stripped electrons, this stunning, deep view of the Lagoon is nearly 100 light-years across.  Right of center, the bright, compact, hourglass shape is gas ionized and sculpted by energetic radiation and extreme stellar winds from a massive young star. In fact, although digitally removed from the featured image, the many bright stars of open cluster NGC 6530 drift within the nebula, just formed in the Lagoon several million years ago.

Image credit: Sameer Dhar
Leaving Earth (2022-08-09)

What it would look like to leave planet Earth? Such an event was recorded visually in great detail by the MESSENGER spacecraft as it swung back past the Earth in 2005 on its way in toward the planet Mercury. Earth can be seen rotating in this time-lapse video, as it recedes into the distance. The sunlit half of Earth is so bright that background stars are not visible. The robotic MESSENGER spacecraft orbit around Mercury from 2011 to 2015 has conducted the first complete map of the surface. On occasion, MESSENGER has continued to peer back at its home world. MESSENGER is one of the few things created on the Earth that will never return.  At the end of its mission MESSENGER crashed into Mercury's surface.