Astronomy Picture of the Day

© Tommy Lease

🌌Kemble’s Cascade of Stars This line of stars is real. A little too faint to see with the unaided eye, Kemble’s Cascade of stars inspires awe when seen with binoculars. Like the Big Dipper though, Kemble’s Cascade is an asterism, not a constellation. The asterism is visible in the northern sky toward the long-necked constellation of the Giraffe (Camelopardalis). This string of about 20 unrelated ...

© Tunc Tezel

🌌After Sunset Planet Parade Look up tonight and see a whole bunch of planets. Just after sunset, looking west, planets Venus, Saturn, Jupiter and Mars will all be simultaneously visible. Listed west to east, this planetary lineup will have Venus nearest the horizon, but setting shortly after the Sun. It doesn't matter where on Earth you live because this early evening planet parade will be visib ...

🌌The Largest Rock in our Solar System There, that dot on the right, that's the largest rock known in our Solar System. It is larger than every known asteroid, moon, and comet nucleus. It is larger than any other local rocky planet. This rock is so large its gravity makes it into a large ball that holds heavy gases near its surface. (It used to be the largest known rock of any type until the rece ...

🌌Moon over Makemake Makemake (sounds like MAH-kay MAH-kay), second brightest dwarf planet of the Kuiper belt, has a moon. Nicknamed MK2, Makemake's moon reflects sunlight with a charcoal-dark surface, about 1,300 times fainter than its parent body. Still, in 2016 it was spotted in Hubble Space Telescope observations intended to search for faint companions with the same technique used to find the ...

© Gabor Balazs

🌌Mars and the Star Clusters At this year's end Mars still shines brightly in planet Earth's night as it wanders through the head-strong constellation Taurus. Its bright yellowish hue dominates this starry field of view that includes Taurus' alpha star Aldebaran and the Hyades and Pleiades star clusters. While red giant Aldebaran appears to anchor the V-shape of the Hyades at the left of the fram ...

© Jason Close

🌌Horsehead and Flame The Horsehead Nebula, famous celestial dark marking also known as Barnard 33, is notched against a background glow of emission nebulae in this sharp cosmic skyscape. About five light-years "tall" the Horsehead lies some 1,500 light-years away in the constellation of Orion. Within the region's fertile molecular cloud complex, the expanse of obscuring dust has a recognizable s ...

© Adam Block

🌌Messier 88 Charles Messier described the 88th entry in his 18th century catalog of Nebulae and Star Clusters as a spiral nebula without stars. Of course the gorgeous M88 is now understood to be a galaxy full of stars, gas, and dust, not unlike our own Milky Way. In fact, M88 is one of the brightest galaxies in the Virgo Galaxy Cluster some 50 million light-years away. M88's beautiful spiral arm ...

© Lukas Moesch

🌌A Full Circle Rainbow over Norway Have you ever seen an entire rainbow? From the ground, typically, only the top portion of a rainbow is visible because directions toward the ground have fewer raindrops. From the air, though, the entire 360-degree circle of a rainbow is more commonly visible. Pictured here, a full-circle rainbow was captured over the Lofoten Islands of Norway in September by a ...

© Russell Croman

🌌NGC 6164: Dragon's Egg Nebula and Halo The star at the center created everything. Known as the Dragon's Egg, this star -- a rare, hot, luminous O-type star some 40 times as massive as the Sun -- created not only the complex nebula (NGC 6164) that immediately surrounds it, but also the encompassing blue halo. Its name is derived, in part, from the region's proximity to the picturesque NGC 6188, ...

© Chuck Derus

🌌Geminids and the Mittens Asteroid 3200 Phaethon's annual gift to planet Earth always arrives in December. Otherwise known as the Geminid meteor shower, the source of the meteroid stream is dust shed along the orbit of the mysterious asteroid. Near the December 13/14 peak of the shower's activity, geminid meteors are captured in this night skyscape, composited from 22 images of starry sky taken ...

© Dan Bartlett

🌌Comet 2022 E3 (ZTF) Comet C/2022 E3 (ZTF) was discovered by astronomers using the wide-field survey camera at the Zwicky Transient Facility this year in early March. Since then the new long-period comet has brightened substantially and is now sweeping across the northern constellation Corona Borealis in predawn skies. It's still too dim to see without a telescope though. But this fine telescopi ...

🌌Cassini Looks Out from Saturn This is what Saturn looks like from inside the rings. In 2017, for the first time, NASA directed the Cassini spacecraft to swoop between Saturn and its rings. During the dive, the robotic spacecraft took hundreds of images showing unprecedented detail for structures in Saturn's atmosphere. Looking back out, however, the spacecraft was also able to capture impressiv ...

© Martin Pugh

🌌NGC 1365: Majestic Island Universe Barred spiral galaxy NGC 1365 is truly a majestic island universe some 200,000 light-years across. Located a mere 60 million light-years away toward the faint but heated constellation Fornax, NGC 1365 is a dominant member of the well-studied Fornax Cluster of galaxies. This impressively sharp color image shows the intense, reddish star forming regions near the ...

© Goran Strand

🌌Sun Halo at Sixty-three Degrees North Happy Solstice! Today is the December solstice, marking an astronomical beginning of summer in the southern hemisphere and winter in the north. On its yearly trek through planet Earth's skies, at this solstice the Sun reaches its southern most declination, 23.5 degrees south, at 21:48 UTC. About 4 days ago the Sun was near this seasonal southern limit and s ...

© Hannah Rochford

🌌Thor's Helmet Thor not only has his own day (Thursday), but a helmet in the heavens. Popularly called Thor's Helmet, NGC 2359 is a hat-shaped cosmic cloud with wing-like appendages. Heroically sized even for a Norse god, Thor's Helmet is about 30 light-years across. In fact, the cosmic head-covering is more like an interstellar bubble, blown with a fast wind from the bright, massive star near t ...

© Craig Stocks

🌌The Tadpole Nebula in Gas and Dust What's causing the commotion in the Tadpole Nebula? Star formation. Dusty emission in the Tadpole Nebula, IC 410, lies about 12,000 light-years away in the northern constellation of the Charioteer (Auriga). The cloud of glowing gas is over 100 light-years across, sculpted by stellar winds and radiation from embedded open star cluster NGC 1893. Formed in the in ...

© Tragoolchitr Jittasaiyapan

🌌25 Brightest Stars in the Night Sky Do you know the names of some of the brightest stars? It's likely that you do, even though some bright stars have names so old they date back to near the beginning of written language. Many world cultures have their own names for the brightest stars, and it is culturally and historically important to remember them. In the interest of clear global communicatio ...

🌌Apollo 17 VIP Site Anaglyph Get out your red/blue glasses and check out this stereo scene from Taurus-Littrow valley on the Moon! The color anaglyph features a detailed 3D view of Apollo 17's Lunar Rover in the foreground -- behind it lies the Lunar Module and distant lunar hills. Because the world was going to be able to watch the Lunar Module's ascent stage liftoff via the rover's TV camera, ...

© Jeff Dai

🌌The Geminid Returning from beyond the Moon, on December 11 the Orion spacecraft entered Earth's atmosphere at almost 11 kilometers per second. That's half the speed of the grain of dust that created this long fireball meteor when it entered the atmosphere on December 13, near the peak of the annual Geminid meteor shower. As our fair planet makes its yearly pass through the dust trail of mysteri ...

© Tomas Slovinsky

🌌Full Moon, Full Mars On December 8 a full Moon and a full Mars were close, both bright and opposite the Sun in planet Earth's sky. In fact Mars was occulted, passing behind the Moon when viewed from some locations across Europe and North America. Seen from the city of Kosice in eastern Slovakia, the lunar occultation of Mars happened just before sunrise. The tantalizing spectacle was recorded i ...

🌌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, the history of constant micrometeorite bombardment has 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 🔗 https://apo ...

© Giulio Cobianchi

🌌An Artful Sky over Lofoten Islands Can the night sky be both art and science? If so, perhaps the featured image is an example. The digital panorama was composed of 10 landscape and 10 sky images all taken on the same night, from the same location, and with the same camera. Iconic features in the image have been artfully brightened, and the ground nearby was artfully illuminated. Visible in the ...

© Bernard Miller

🌌An Unusual Globule in IC 1396 Is there a monster in IC 1396? Known to some as the Elephant's Trunk Nebula, parts of gas and dust clouds of this star formation region may appear to take on foreboding forms, some nearly human. The only real monster here, however, is a bright young star too far from Earth to hurt us. Energetic light from this star is eating away the dust of the dark cometary globu ...

🌌Io in True Color The strangest moon in the Solar System is bright yellow. The featured picture, an attempt to show how Io would appear in the "true colors" perceptible to the average human eye, was taken in 1999 July by the Galileo spacecraft that orbited Jupiter from 1995 to 2003. Io's colors derive from sulfur and molten silicate rock. The unusual surface of Io is kept very young by its syste ...

🌌America and the Sea of Serenity Get out your red/blue glasses and check out this stereo view of another world. Fifty years ago the scene was recorded by Apollo 17 mission commander Eugene Cernan on December 11, 1972, one orbit before descending to land on the Moon. The stereo anaglyph was assembled from two photographs (AS17-147-22465, AS17-147-22466) captured from his vantage point on board th ...