juliensimon/nasa-apod huggingface dataset:
Comet R3 (PanSTARRS) Brightens (2026-04-12)

Comet R3 is brightening rapidly -- will it survive?  C/2025 R3 (PanSTARRS) has been slowly brightening and extending an ion tail since its discovery last year.  This shedding mountain of dirty ice puts on its best sky show this month, though, because it passes its closest to both the Sun (April 19) and the Earth (April 25).  The featured image, showing R3 already sporting a tail extending over 10 degrees, was taken two nights ago from Sion, Switzerland with the big mountain Bietschhorn on the left.  Comet R3 will be visible during mid-April before sunrise. Although the future brightness of any comet is hard to predict, the brightness of R3 makes it already a good camera comet and it may become visible to the unaided eye in the next week.  Comet R3's physical future is also unknown because, like Comet A1 (MAPS) earlier this month, it may disintegrate when it passes its closest to the Sun.  Or it may live to leave the Solar System.    Growing Gallery: Comet R3 in 2026

Image credit: José Rodrigues
NGC 602 and Beyond (2026-04-13)

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 5 million year young star cluster NGC 602. Surrounded by natal gas and dust, NGC 602 is featured in this stunning Hubble image of the region. Fantastic ridges and swept back shapes 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 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 multi-colored view. The background galaxies are hundreds of millions of light-years or more beyond NGC 602.   Sky Surprise: What picture did APOD feature on your birthday? (after 1995)
The Long Wispy Tail of Comet R3 (PanSTARRS) (2026-04-14)

Why does Comet R3 (PanSTARRS) have a wispy tail?  The newest bright member of the inner Solar System, Comet C/2025 R3 (PanSTARRS) is already extending an impressive stream of glowing gas. This tail starts from an unseen central nucleus of dirty ice that is likely a few kilometers across. The nucleus is warmed by the Sun and emits a cloud of neutral gas into a coma that glows light green. Nuclear gas ionized by energetic sunlight is pushed away from the Sun by the solar wind into an ion tail that glows light blue.  The wispy nature of the ion tail is caused by the constantly changing structure of the solar wind.  Pictured from Rhode Island, USA two days ago, Comet R3 (PanSTARRS) shows off a many-degree ion tail.  Comet R3 (PanSTARRS) is best seen before dawn from northern skies for another 10 days, after which it will be best visible from southern skies.    Growing Gallery: Comet R3 in 2026

Image credit: Haythem Hamdi
The ISS Transits the Moon (2026-04-15)

Nope, that is not an alien spaceship landing on the Moon! This is an image of the International Space Station (ISS) as it begins to transit in front of the Moon. The ISS is in low-Earth orbit (LEO) where it wizzes around the Earth every 90 minutes. Orbiting the Earth 16 times per day	 for 25 years, the ISS has photobombed many familiar celestial objects including Venus, Mars, Saturn, and the Sun. Thousands of experiments led by researchers from over one hundred countries have been conducted on the ISS. Growing protein crystals in low gravity was one of the first experiments onboard the ISS and continues to contribute to new medical treatments. ISS astronauts study plant growth, water recycling, human health, and more to support the Artemis missions which will take humans farther than they’ve ever gone before. Next time you are out and about at night, try to  spot the ISS zooming across the sky!

Image credit: Sébastien Borie

Text:
Keighley Rockcliffe  
(NASA
GSFC, 
UMBC CSST, 
CRESST II)
South Celestial Tree (2026-04-16)

If you live in the northern hemisphere, you may have learned how to locate the North Star, Polaris, in the night sky. It can be used to find north, and it approximately marks the northern celestial pole. If you live in the southern hemisphere, there is no bright star marking the southern celestial pole, but the Southern Cross can be used to find south. The featured image was taken in Padre Bernardo (GO), Brazil. It shows the apparent motion of the stars around the apparently empty southern celestial pole over 2 hours, on August 20, 2018. Each star takes about 24 hours to make a complete turn around the pole in the sky. Padre Bernardo is located in the Cerrado region, a tropical savanna that occupies most of central Brazil and supports rich biodiversity. The barren branch that apparently supports this sky wheel of rotating stars is a common sight there in the dry season during the southern winter.

Image credit: Kiko Fairbairn
M82: Starburst Galaxy with a Superwind (2026-04-17)

Messier 82 is a starburst galaxy with a superwind. In fact, through supernova explosions and powerful winds from massive stars, the burst of star formation in M82 is driving a prodigious outflow. Evidence for the superwind from the galaxy's central regions is clear in the sharp telescopic portrait. The composite image includes 33 hours of narrowband data, highlighting emission from long outflow filaments of atomic hydrogen gas in reddish hues. Some of the gas in the superwind, enriched in heavy elements forged in the massive stars, will eventually escape into intergalactic space. Triggered by a close encounter with nearby large galaxy M81, the furious burst of star formation in M82 should last about 100 million years or so. Also known as the Cigar Galaxy for its elongated visual appearance, M82 is about 30,000 light-years across. It lies 12 million light-years away near the northern boundary of Ursa Major.

Image credit: Arnaud Malleval
PanSTARRS and Planets (2026-04-18)

Near the eastern horizon before sunrise, Comet C/2025 R3 PanSTARRS is getting brighter. Readily visible in binoculars and small telescopes, the comet may be just on the verge of naked-eye visibility from dark sky sites. Though it was not quite apparent to the eye, PanSTARRS is still easy to spot in this camera image taken on April 16. In the view from a volcanic peak overlooking France's Reunion Island, planet Earth, the comet shares eastern predawn skies with naked-eye planets Mars and Mercury and fainter Neptune. Saturn is hiding behind the low cloudbank that doesn't quite hide an old crescent Moon. This is a good weekend for northern hemisphere comet watchers to try to catch PanSTARRS an hour or so before sunrise, as the comet grows brighter approaching its perihelion on April 19. On April 26 the comet makes its closest approach to our fair planet but by then will be difficult to see in the solar glare. Good views of this comet PanSTARRS in late April and early May will be from the southern hemisphere.

Image credit: Luc Perrot
Eye on the Milky Way (2026-04-19)

Have you ever had stars in your eyes? It appears that the eye on the left does, and moreover, it appears to be gazing at even more stars. The featured 27-frame mosaic was taken in 2019 from Ojas de Salar in the Atacama Desert of Chile.  The eye is actually a small lagoon captured reflecting the dark night sky as the Milky Way Galaxy arched overhead. The seemingly smooth band of the Milky Way is really composed of billions of stars, but decorated with filaments of light-absorbing dust and red-glowing nebulas. Additionally, both Jupiter (slightly left the galactic arch) and Saturn (slightly to the right) are visible.  The lights of small towns dot the unusual vertical horizon.  The rocky terrain around the lagoon appears to some more like the surface of Mars than our Earth.   Sky Surprise: What picture did APOD feature on your birthday? (after 1995)

Image credit: Miguel Claro
(TWAN,
Dark Sky Alqueva)
Comet R3 PanSTARRS over a Himalayan Valley (2026-04-20)

The best way to see comet R3 PanSTARRS’s long tail is with a camera. This week, the recently brightened comet appears in northern skies to the east just before dawn, but is only barely visible to the unaided eye. The many-degree ion tail captured on long duration camera exposures is not unusual for a comet - it is primarily due to the Earth's nearly sideways view of the tail as it points away from the Sun.  In the featured image taken last week, Comet C/2025 R3 (PanSTARRS) showed off its flowing tail through a valley between two peaks in the Himalayan mountains of India.   The comet passed its closest to the Sun yesterday. As it nears its closest approach to Earth next week, a bushy dust tail may become visible.  The comet is slowly moving out of northern skies and by the end of the month will be visible after sunset in southern skies as it fades and leaves our Solar System.    Growing Gallery: Comet R3 PanSTARRS in 2026

Image credit: Basudeb Chakrabarti & 
Samit Saha
Three Sky Arches over Snowy Alps (2026-04-21)

Why are there three arches across the sky instead of two? Last month, after being dropped off by a helicopter at a high mountain peak in the Alps near the Swiss Italian border, an adventurous astrophotographer expected two arches of our Milky Way galaxy to be visible during the night. These were the inner arch looking in toward the center of our galaxy on the left, visible just before sunrise, and the outer arch on the right visible just after sunset.  But there were three arches. The surprised astrophotographer soon realized that the sky was so dark that an entire arc of faint zodiacal light was also noticeable -- sunlight scattered by inner Solar System dust.  And it artfully connected the two Milky Way arches!  The next morning a helicopter picked the astrophotographer back up, and after 40 hours of processing and combining that night's images, the featured triple-arch 360-degree panorama resulted.    Jigsaw Vistas: Astronomy Puzzle of the Day

Image credit: Angel Fux
Earthset with an iPhone (2026-04-22)

What does it mean for the Earth to set? Artemis II Commander Reid Wiseman gave us another spectacular view of Earth from their historic flyby of the Moon. Commander Wiseman's video, taken with an iPhone at 8x zoom, shows our entire planet gradually blocked from view by the Moon. On the Earth, the 24-hour planetary rotation causes the Sun to set below your horizon every night. However, on Artemis II the Earthset was caused not by the Moon’s rotation but by the spacecraft moving behind the Moon (at about 55 seconds in this video). Once rare, views of Earth are now taken many times a day from many spacecraft, including NASA’s SWOT (Surface Water and Ocean Topography) satellite tracking freshwater resources and USGS Landsat 8 and 9 satellites supporting water management for farmers, for example. Space agencies around our home planet now work together to provide unique and ever-improving views of our Earth.   Celebrate: Earth Day
Large Scale Structure of the Universe (2026-04-23)

This is a map of the universe. The Dark Energy Spectroscopic Instrument (DESI) at Kitt Peak National Observatory, Arizona, has finished its five-year survey. It observed more than 47 million galaxies and quasars and created a 3D map centered on the Earth. Today's featured image shows a thin slice of these data: the black gaps indicate where our Galaxy obscures distant objects. The feathery web in the inset shows the large scale structure of the universe. Light of the most distant galaxies shown here travelled for 11 billion years to reach the Earth. Galaxies cluster throughout cosmic history under the competing influences of gravity and dark energy, responsible for the accelerated expansion of the universe. Analysis of early DESI results hinted at the possibility that dark energy, described as a cosmological constant by Albert Einstein, may not be constant after all. But we still have to wait for the analysis of the now complete dataset. The nature of dark energy is the biggest mystery of cosmology.
Young Moon and Sister Stars (2026-04-24)

Sunlit arms of a crescent moon seem to embrace the faint lunar night side in this dramatic celestial view from planet Earth. The single telephoto exposure tracking the sky was captured on the night of April 19, when a two day old Moon was near perigee in its elliptical orbit. On that date, the young Moon was also close on the sky to the lovely Pleiades Star Cluster. With the moonlight dimmed by clouds the Pleiades sister stars gather below the Moon's bright crescent, seen through a faint but colorful lunar corona. The lunar night side is illuminated by earthshine, sunlight reflected from the Earth itself. The Moon's ashen glow, also known as the "old moon in the young moon's arms," tends to be bright in the northern hemisphere spring. And for now, the Moon's orbit takes it near the Pleiades stars each month in planet Earth's sky, though their close conjunctions are easiest to see when the Moon is near a crescent phase.

Image credit: Giorgia Hofer
The Persistence of Sunlight (2026-04-25)

This seaside sunset offered a surreal experience, captured in a sea and skyscape from the west coast of Sardinia, Italy, planet Earth. The Daliesque scene is a composition of sequential exposures made with a camera and long telephoto lens. The Sun is not melting, though. Its shifting and fluid appearance as it nears the horizon is caused as refraction along the line of sight changes and creates distorted images or mirages of the reddened solar disk. The changes in atmospheric refraction correspond to atmospheric layers with sharply different temperatures and densities. Another famous but fleeting effect of atmospheric refraction produced by a long sight-line to the setting (or rising) Sun is often called the green flash.

Image credit: Lorenzo Busilacchi
Mystic Mountain Monster being Destroyed (2026-04-26)

Inside the head of this interstellar monster is a star that is slowly destroying it.  The huge monster, actually an inanimate series of pillars of gas and dust, measures light years in length.  The in-head star is not itself visible through the opaque interstellar dust but is bursting out partly by ejecting opposing beams of energetic particles called Herbig-Haro jets.  Located about 7,500 light years away in the Carina Nebula and known informally as Mystic Mountain, the appearance of these pillars is dominated by dark dust even though they are composed mostly of clear hydrogen gas.  The featured image was taken with the Hubble Space Telescope. All over these pillars, the energetic light and winds from massive newly formed stars are evaporating and dispersing the dusty stellar nurseries in which they formed.  Within a few million years, the head of this giant, as well as most of its body, will have been completely evaporated by internal and surrounding stars.