Astronomy Picture of the Day

🌌M41: The Little Beehive Star Cluster Why are there so many bright blue stars? Stars are usually born in clusters, and the brightest and most massive of these stars typically glow blue. Less-bright, non-blue stars like our Sun surely also exist in this M41 star cluster but are harder to see. A few bright orange-appearing red giant stars are visible. The red-light filaments are emitted by diffuse ...

© Davide Caliò

🌌Light Pillar over Erupting Etna Can a lava flow extend into the sky? No, but light from the lava flow can. One effect is something quite unusual -- a volcanic light pillar. More typically, light pillars are caused by sunlight and so appear as a bright column that extends upward above a rising or setting Sun. Alternatively, other light pillars -- some quite colorful -- have been recorded above s ...

🌌Saturn in Infrared from Cassini Saturn looks slightly different 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 s ...

© Vincenzo Mirabella

🌌Rima Hyginus Rima Hyginus is a spectacular fissure, some 220 kilometers long, found near the center of the lunar near side. Easy to spot in telescopic views of the Moon, it stretches top left to bottom right across this lunar closeup. The image was made with exaggerated colors that reflect the mineral composition of the lunar soil. Hyginus crater lies near the center of the narrow lunar surface ...

🌌Hubble's Andromeda Galaxy Mosaic The largest photomosaic ever assembled from Hubble Space Telescope image data is a panoramic view of our neighboring spiral Andromeda Galaxy. With 600 overlapping frames assembled from observations made from July 2010 to December 2022, the full Hubble Andromeda Galaxy mosaic spans almost six full moons across planet Earth's sky. A cropped version shown above is ...

🌌Messier 87 rmous elliptical galaxy Messier 87 is about 50 million light-years away. Also known as NGC 4486, the giant galaxy holds trillions of stars compared to the mere billions of stars in our large spiral Milky Way. M87 reigns as the large central elliptical galaxy in the Virgo galaxy cluster. An energetic jet from the giant galaxy's core is seen to stretch outward for about 5,000 light-yea ...

🌌HH 30: A Star System with Planets Now Forming How do stars and planets form? New clues have been found in the protoplanetary system Herbig-Haro 30 by the James Webb Space Telescope in concert with Hubble and the Earth-bound ALMA. The observations show, among other things, that large dust grains are more concentrated into a central disk where they can form planets. The featured image from Webb s ...

© Nicolas Martino, Adrien Soto, Louis Leroux & Yann Sainty

🌌Thor's Helmet versus the Seagull Seen as a seagull and a duck, these nebulae are not the only cosmic clouds to evoke images of flight. But both are winging their way across this broad celestial landscape, spanning almost 7 degrees across planet Earth's night sky toward the constellation of the Big Dog (Canis Major). The expansive Seagull (top center) is itself composed of two major cataloged em ...

© Martin LaMontagne

🌌SpaceX Rocket Launch Plume over California What's happened to the sky? Last Monday, the photogenic launch plume from a SpaceX rocket launch created quite a spectacle over parts of southern California and Arizona. Looking at times like a giant space fish, the impressive rocket launch from Vandenberg Air Force Base near Lompoc, California, was so bright because it was backlit by the setting Sun. ...

🌌Perijove 11: Passing Jupiter Here comes Jupiter. NASA's robotic spacecraft Juno is continuing on its highly elongated orbits around our Solar System's largest planet. The featured video is from perijove 11 in early 2018, the eleventh time Juno passed near Jupiter since it arrived in mid-2016. This time-lapse, color-enhanced movie covers about four hours and morphs between 36 JunoCam images. The ...

© planet Earth

🌌Parhelia at Abisko Three suns seem to hug the horizon in this otherworldly winterscape. But the evocative scene was captured during a February 3rd snowmobile exploration of the mountainous region around Abisko National Park, northern Sweden, planet Earth. The two bright spots on either side of Earth's Sun are parhelia (singular parhelion), also known as mock suns or sun dogs. The parhelia are c ...

© Harry Karamitsos

🌌A Cosmic Rose: NGC 2237 in Monoceros The Rosette Nebula, NGC 2237, is not the only cosmic cloud of gas and dust to evoke the imagery of flowers, but it is probably the most famous. At the edge of a large molecular cloud in Monoceros some 5,000 light years away, the petals of this cosmic rose are actually a stellar nursery. The lovely, symmetric shape is sculpted by the winds and radiation from ...

© Roberto Marinoni

🌌Reflections on VdB 31 Riding high in the constellation of Auriga, beautiful, blue VdB 31 is the 31st object in Sidney van den Bergh's 1966 catalog of reflection nebulae. It shares this well-composed celestial still life with dark, obscuring clouds B26, B27, and B28, recorded in Edward E. Barnard's 1919 catalog of dark markings in the sky. All are these nebulae are interstellar dust clouds. Barn ...

🌌Asteroid Bennu Holds the Building Blocks of Life What can a space rock tell us about life on Earth? NASA's OSIRIS-REx spacecraft made a careful approach to the near-Earth asteroid 101955 Bennu in October of 2020 to collect surface samples. In September 2023, the robotic spaceship returned these samples to Earth. A recent analysis has shown, surprisingly, that the samples contained 14 out of the ...

© Dave Boddington

🌌The Spider and the Fly Will the spider ever catch the fly? Not if both are large emission nebulas toward the constellation of the Charioteer (Auriga). The spider-shaped gas cloud in the image center is actually an emission nebula labelled IC 417, while the smaller fly-shaped cloud on the left is dubbed NGC 1931 and is both an emission nebula and a reflection nebula. About 10,000 light-years dis ...

© Mickael Coulon

🌌Auroral Hummingbird over Norway Is this the largest hummingbird ever? Although it may look like a popular fluttering nectarivore, what is pictured is actually a beautifully detailed and colorful aurora, complete with rays reminiscent of feathers. This aurora was so bright that it was visible to the unaided eye during blue hour -- just after sunset when the sky appears a darkening blue. However, ...

© Michael Goh

🌌Milky Way over the Australian Pinnacles What strange world is this? Earth. In the foreground of the featured image are the Pinnacles, unusual rock spires in Nambung National Park in Western Australia. Made of ancient sea shells (limestone), how these human-sized picturesque spires formed remains unknown. In the background, just past the end of the central Pinnacle, is a bright crescent Moon. Th ...

© Aldo S. Kleiman

🌌A Conjunction of Crescents A waxing crescent Moon and a waning crescent Venus are found at opposite corners of this twilight telephoto field of view. The close conjunction of the two brightest celestial beacons in planet Earth's western evening sky was captured on February 1 from Rosario, Argentina. On that date, the slender crescent Moon was about 3 days old. But the Moon's visible sunlit cres ...

🌌LEDA 1313424: The Bullseye Galaxy The giant galaxy cataloged as LEDA 1313424 is about two and a half times the size of our own Milky Way. Its remarkable appearance in this recently released Hubble Space Telescope image strongly suggests its nickname "The Bullseye Galaxy". Known as a collisional ring galaxy it has nine rings confirmed by telescopic observations, rippling from its center like wav ...

© Lorand Fenyes

🌌IC 2574: Coddington's Nebula Grand spiral galaxies often seem to get all the glory, flaunting their young, bright, blue star clusters in beautiful, symmetric spiral arms. But small, irregular galaxies form stars too. In fact dwarf galaxy IC 2574 shows clear evidence of intense star forming activity in its telltale reddish regions of glowing hydrogen gas. Just as in spiral galaxies, the turbulen ...

🌌Comet G3 ATLAS Setting over a Chilean Hill Where is Comet ATLAS going? In the featured time-lapse video, the comet is not itself moving very much, but the Earth's rotation makes it appear to be setting over a hill. The Comet C/2024 G3 (ATLAS) sequence was captured with an ordinary camera on January 22 from the Araucanía Region in central Chile. Comet ATLAS has been an impressive site in the eve ...

© Julene Eiguren

🌌Anticrepuscular Rays: A Rainbow Fan over Spain Yes, but can your rainbow do this? Late in the day, the Sun set as usual toward the west. However, on this day, the more interesting display was 180 degrees around -- toward the east. There, not only was a rainbow visible, but an impressive display of anticrepuscular rays from the rainbow's center. In the featured image from Lekeitio in northern Sp ...

🌌Wolf-Rayet Star 124: Stellar Wind Machine Some stars explode in slow motion. Rare, massive Wolf-Rayet stars are so tumultuous and hot that they are slowly disintegrating right before our telescopes. Glowing gas globs each typically over 30 times more massive than the Earth are being expelled by violent stellar winds. Wolf-Rayet star WR 124, visible near the featured image center and spanning si ...

🌌Comet G3 ATLAS Disintegrates What's happening to Comet G3 ATLAS? After passing near the Sun in mid-January, the head of the comet has become dimmer and dimmer. By late January, Comet C/2024 G3 (ATLAS) had become a headless wonder -- even though it continued to show impressive tails after sunset in the skies of Earth's Southern Hemisphere. Pictured are images of Comet G3 ATLAS on successive Janu ...

© Known as nacreous clouds

🌌Nacreous Clouds over Sweden Vivid and lustrous, wafting iridescent waves of color wash across this skyscape from northern Sweden. Known as nacreous clouds or mother-of-pearl clouds, they are rare. But their unforgettable appearance was captured in this snapshot on January 12 with the Sun just below the local horizon. A type of polar stratospheric cloud, they form when unusually cold temperature ...

© Tommy Lease

🌌The Variable Nebula NGC 2261 The interstellar cloud of dust and gas captured in this sharp telescopic snapshot is seen to change its appearance noticeably over periods as short as a few weeks. Discovered over 200 years ago and cataloged as NGC 2261, bright star R Monocerotis lies at the tip of the fan-shaped nebula. About one light-year across and 2500 light-years away, NGC 2261 was studied ear ...

© Pea Mauro

🌌Hydrogen Clouds of M33 Gorgeous spiral galaxy Messier 33 seems to have more than its fair share of glowing hydrogen gas. A prominent member of the local group of galaxies, M33 is also known as the Triangulum Galaxy and lies a mere 3 million light-years away. The galaxy's central 60,000 light-years or so are shown in this sharp galaxy portrait. The portrait features M33's reddish ionized hydroge ...