Astronomy Picture of the Day

© Dan Bartlett

🌌Comet C/2025 F2 SWAN In late March, the comet now designated C/2025 F2 SWAN was found independently by citizen scientists Vladimir Bezugly, Michael Mattiazzo, and Rob Matson while examining publicly available image data from the Solar Wind ANisotropies (SWAN) camera on the sun-staring SOHO spacecraft. Comet SWAN's coma, its greenish color a signature of diatomic carbon molecules fluorescing in ...

© Daniel Adibi

🌌Virgo Cluster Galaxies Galaxies of the Virgo Cluster are scattered across this nearly 4 degree wide telescopic field of view. About 50 million light-years distant, the Virgo Cluster is the closest large galaxy cluster to our own local galaxy group. Prominent here are Virgo's bright elliptical galaxies from the Messier catalog, M87 at bottom left, and M86 and M84 near center right. M86 and M84 a ...

© Taavi Niittee (Tõrva Astronomy Club)

🌌Halo of the Cat's Eye 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 ...

🌌Planetary Nebula NGC 1514 from Webb What happens when a star runs out of nuclear fuel? For stars like our Sun, the center condenses into a white dwarf while the outer atmosphere is expelled into space to appear as a planetary nebula. The expelled outer atmosphere of planetary nebula NGC 1514 appears to be a jumble of bubbles -- when seen in visible light. But the view from the James Webb Space ...

🌌The Galactic Center in Radio from MeerKAT What's happening at the center of our galaxy? It's hard to tell with optical telescopes since visible light is blocked by intervening interstellar dust. In other bands of light, though, such as radio, the galactic center can be imaged and shows itself to be quite an interesting and active place. The featured picture shows an image of our Milky Way's cen ...

🌌An Unusual Hole in Mars What created this unusual hole in Mars? Actually, there are numerous holes pictured in this Swiss cheese-like landscape, with all-but-one of them showing a dusty, dark, Martian terrain beneath evaporating, light, carbon dioxide ice. The most unusual hole is on the upper right, spans about 100 meters, and seems to punch through to a lower level. Why this hole exists and w ...

© Jordi Coy

🌌Moon Near the Edge Most of us watch the Moon at night. But the Moon spends nearly as many daylight hours above our horizon, though in bright daytime skies the lunar disk looks pale and can be a little harder to see. Of course in daytime skies the Moon also appears to cycle through its phases, shining by reflected sunlight as it orbits our fair planet. For daytime moonwatchers, the Moon is proba ...

© A.J. Smadi

🌌The ISS Meets Venus Made with a telescope shaded from bright sunlight by an umbrella, on April 5 a well-planned video captured a crescent Venus shining in clear daytime skies from Shoreline, Washington, USA at 11:57AM Pacific Time. It also caught the International Space Station in this single video frame. In close conjunction with the bright planet, the faint outline of the orbital outpost seen ...

© Daniel Yang K.

🌌38 Hours with the M81 Group From a garden on planet Earth, 38 hours of exposure with a camera and small telescope produced this cosmic photo of the M81 galaxy group. In fact, the group's dominant galaxy M81 is near the center of the frame sporting grand spiral arms and a bright yellow core. Also known as Bode's galaxy, M81 itself spans some 100,000 light-years. Near the top is cigar-shaped irre ...

🌌HH 49: Interstellar Jet from Webb What's at the tip of this interstellar jet? First let's consider the jet: it is being expelled by a star system just forming and is cataloged as Herbig-Haro 49 (HH 49). The star system expelling this jet is not visible -- it is off to the lower right. The complex conical structure featured in this infrared image by the James Webb Space Telescope also includes a ...

🌌Moon Visits Sister Stars Sometimes, the Moon visits the Pleiades. Technically, this means that the orbit of our Moon takes it directly in front of the famous Pleiades star cluster, which is far in the distance. The technical term for the event is an occultation, and the Moon is famous for its rare occultations of all planets and several well-known bright stars. The Moon's tilted and precessing ...

🌌NGC 4414: A Flocculent Spiral Galaxy How much mass do flocculent spirals hide? The featured image of flocculent spiral galaxy NGC 4414 was taken with the Hubble Space Telescope to help answer this question. Flocculent spirals -- galaxies without well-defined spiral arms -- are a quite common form of galaxy, and NGC 4414 is one of the closest. Stars and gas near the visible edge of spiral galaxi ...

🌌Moonquakes Surprisingly Common Why are there so many moonquakes? 🔗 https://apod.nasa.gov/apod/ap250406.html

© Bertrand Kulik

🌌The Gargoyles' Eclipse In dramatic silhouette against a cloudy daytime sky over Paris, France, gargoyles cast their monstrous gaze outward from the west facade of Notre Dame Cathedral. Taken on March 29, this telephoto snapshot also captures the dramatic silhouette of a New Moon against the bright solar disk in a partial solar eclipse. Happening high in Parisian skies, the partial eclipse was c ...

© Jiang Wu

🌌Hickson 44 in Leo Scanning the skies for galaxies, Canadian astronomer Paul Hickson and colleagues identified some 100 compact groups of galaxies, now appropriately called Hickson Compact Groups. The four prominent galaxies seen in this intriguing telescopic skyscape are one such group, Hickson 44. The galaxy group is about 100 million light-years distant, far beyond the spiky foreground Milky ...

© Giorgia Hofer

🌌The Da Vinci Glow A 26 hour old Moon poses behind the craggy outline of the Italian Dolomites in this twilight mountain and skyscape. The one second long exposure was captured near moonset on March 30. And while only a a sliver of its sunlit surface is visible, most of the Moon's disk can be seen by earthshine as light reflected from a bright planet Earth illuminates the lunar nearside. Also kn ...

🌌Jupiter and Ring in Infrared from Webb 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 t ...

🌌A Double Sunrise from a Partial Eclipse Can the Sun appear to rise twice at the same time? This was just the case a few days ago from Les Escoumins, Quebec, Canada as our Solar System's bright central orb rose just as it was being partially eclipsed by the Moon. The featured video shows this unusual double-sunrise in real time and being reflected by the St. Lawrence River. Soon after the initia ...

🌌Parker: The Solar System from Near the Sun If you watch long enough, a comet will appear. Before then, you will see our Solar System from inside the orbit of Mercury as recorded by NASA's Parker Solar Probe looping around the Sun. The video captures coronal streamers into the solar wind, a small Coronal Mass Ejection, and planets including, in order of appearance, Mercury, Venus, Saturn, Earth, ...

© Wioleta Gorecka

🌌A Partial Solar Eclipse over Iceland What if the Sun and Moon rose together? That happened yesterday over some northern parts of planet Earth as a partial solar eclipse occurred shortly after sunrise. Regions that experienced the Moon blocking part of the Sun included northeastern parts of North America and northwestern parts of Europe, Asia, and Africa. The featured image was captured yesterda ...

🌌Stereo Helene Get out your red/blue glasses and float next to Helene, small, icy moon of Saturn. Appropriately named, Helene is a Trojan moon, so called because it orbits at a Lagrange point. A Lagrange point is a gravitationally stable position near two massive bodies, in this case Saturn and larger moon Dione. In fact, irregularly shaped ( about 36 by 32 by 30 kilometers) Helene orbits at Dio ...

🌌Lunar Dust and Duct Tape Why is the Moon so dusty? On Earth, rocks are weathered by wind and water, creating soil and sand. On the Moon, eons of constant micrometeorite bombardment have blasted away at the rocky surface creating a layer of powdery lunar soil or regolith. For the Apollo astronauts and their equipment, the pervasive, fine, gritty dust was definitely a problem. On the lunar surfac ...

© Lorand Fenyes

🌌Messier 81 One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful Messier 81. Also known as NGC 3031 or Bode's galaxy for its 18th century discoverer, this grand spiral can be found toward the northern constellation of Ursa Major, the Great Bear. The sharp, detailed telescopic view reveals M81's bright yellow nucleus, blue spiral arms, pin ...

© Juan Montilla (AAE)

🌌Star Formation in the Pacman Nebula You'd think the Pacman Nebula would be eating stars, but actually it is forming them. Within the nebula, a cluster's young, massive stars are powering the pervasive nebular glow. The eye-catching shapes looming in the featured portrait of NGC 281 are sculpted dusty columns and dense Bok globules seen in silhouette, eroded by intense, energetic winds and radia ...

© Zixiong Jin

🌌A Blue Banded Blood Moon What causes a blue band to cross the Moon during a lunar eclipse? The blue band is real but usually quite hard to see. The featured HDR image of last week's lunar eclipse, however -- taken from Norman, Oklahoma (USA) -- has been digitally processed to exaggerate the colors. The gray color on the upper right of the top lunar image is the Moon's natural color, directly il ...

🌌Ancient Ogunquit Beach on Mars This was once a beach -- on ancient Mars. The featured 360-degree panorama, horizontally compressed, was taken in 2017 by the robotic Curiosity rover that explored the red planet. Named Ogunquit Beach after its terrestrial counterpart, evidence shows that at times long ago the area was underwater, while at other times it was at the edge of an ancient lake. The lig ...