Astronomy Picture of the Day

🌌Jupiter over 2 Hours and 30 Minutes Jupiter, our Solar System's ruling gas giant, is also the fastest spinning planet, rotating once in less than 10 hours. The gas giant doesn't rotate like a solid body though. A day on Jupiter is about 9 hours and 56 minutes long at the poles, decreasing to 9 hours and 50 minutes near the equator. The giant planet's fast rotation creates strong jet streams, se ...

© Ralf Rohner

🌌Northern Lights from the Stratosphere Northern lights shine in this night skyview from planet Earth's stratosphere, captured on January 15. The single, 5 second exposure was made with a hand-held camera on board an aircraft above Winnipeg, Canada. During the exposure, terrestrial lights below leave colorful trails along the direction of motion of the speeding aircraft. Above the more distant ho ...

© Gene Cernan

🌌America and the Sea of Serenity Get out your red/blue glasses and check out this stereo view of another world. 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 the Lunar Module C ...

© Michele Guzzini

🌌The Orion You Can Almost See Do you recognize this constellation? Although it is one of the most recognizable star groupings on the sky, this is a more full Orion than you can see -- an Orion only revealed with long exposure digital camera imaging and post- processing. Here the cool red giant Betelgeuse takes on a strong orange tint as the brightest star on the upper left. Orion's hot blue star ...

🌌Star Cluster IC 348 from Webb Sometimes, it's the stars that are the hardest to see that are the most interesting. IC 348 is a young star cluster that illuminates surrounding filamentary dust. The stringy and winding dust appears pink in this recently released infrared image from the Webb Space Telescope. In visible light, this dust reflects mostly blue light, giving the surrounding material th ...

© Jingyi Zhang & Wang Zheng

🌌Dragon Aurora over Iceland Have you ever seen a dragon in the sky? Although real flying dragons don't exist, a huge dragon-shaped aurora developed in the sky over Iceland in 2019. The aurora was caused by a hole in the Sun's corona that expelled charged particles into a solar wind that followed a changing interplanetary magnetic field to Earth's magnetosphere. As some of those particles then st ...

© Radoslav Zboran

🌌Circling the Sun rth's orbit around the Sun is not a circle, it's an ellipse. The point along its elliptical orbit where our fair planet is closest to the Sun is called perihelion. This year, perihelion was on January 2 at 01:00 UTC, with the Earth about 3 million miles closer to the Sun than it was at aphelion (last July 6), the farthest point in its elliptical orbit. Of course, distance from ...

© Michael Luy

🌌Good Morning Moon Yesterday, the Moon was New. But on January 9, early morning risers around planet Earth were treated to the sight of an old Moon, low in the east as the sky grew bright before dawn. Above the city of Saarburg in Rhineland-Palatinate, western Germany, this simple snapshot found the waning Moon's sunlit crescent just before sunrise. But also never wandering far from the Sun in E ...

© 염범석 Yeom Beom-seok

🌌Quadrantids of the North Named for a forgotten constellation, the Quadrantid Meteor Shower puts on an annual show for planet Earth's northern hemisphere skygazers. The shower's radiant on the sky lies within the old, astronomically obsolete constellation Quadrans Muralis. That location is not far from the Big Dipper asterism, known to some as the Plough, at the boundaries of the modern constell ...

© Gábor Galambos

🌌The Light, the Dark, and the Dusty This colorful skyscape spans about three full moons across nebula rich starfields along the plane of our Milky Way Galaxy toward the royal northern constellation Cepheus. Near the edge of the region's massive molecular cloud some 2,400 light-years away, bright reddish emission region Sharpless (Sh)2-155 is at the center of the frame, also known as the Cave Neb ...

© Ritesh Biswas

🌌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 ...

🌌The Phases of Venus Venus goes through phases. Just like our Moon, Venus can appear as a full circular disk, a thin crescent, or anything in between. Venus, frequently the brightest object in the post-sunset or pre-sunrise sky, appears so small, however, that it usually requires binoculars or a small telescope to clearly see its current phase. The featured time-lapse sequence was taken over the ...

🌌The Cat's Eye Nebula in Optical and X-ray To some it looks like a cat's eye. To others, perhaps like a giant cosmic conch shell. It is actually one of the brightest and most highly detailed planetary nebula known, composed of gas expelled in the brief yet glorious phase near the end of life of a Sun-like star. This nebula's dying central star may have produced the outer circular concentric shel ...

🌌The Snows of Churyumov-Gerasimenko You couldn't really be caught in this blizzard while standing by a cliff on periodic comet 67P/Churyumov-Gerasimenko. Orbiting the comet in June of 2016, the Rosetta spacecraft's narrow angle camera did record streaks of dust and ice particles similar to snow as they drifted across the field of view close to the camera and above the comet's surface. Still, som ...

© Fred Zimmer

🌌Trapezium: At the Heart of Orion Near the center of this sharp cosmic portrait, at the heart of the Orion Nebula, are four hot, massive stars known as the Trapezium. Gathered within a region about 1.5 light-years in radius, they dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet ionizing radiation from the Trapezium stars, mostly from the brightest star Theta-1 Orionis C powe ...

🌌Zeta Oph: Runaway Star Like a ship plowing through cosmic seas, runaway star Zeta Ophiuchi produces the arcing interstellar bow wave or bow shock seen in this stunning infrared portrait. In the false-color view, bluish Zeta Oph, a star about 20 times more massive than the Sun, lies near the center of the frame, moving toward the left at 24 kilometers per second. Its strong stellar wind precedes ...

© Tristian McDonald; Text: Tiffany Lewis (Michigan Tech U.)

🌌A SAR Arc from New Zealand What is that unusual red halo surrounding this aurora? It is a Stable Auroral Red (SAR) arc. SAR arcs are rare and have only been acknowledged and studied since 1954. The featured wide-angle photograph, capturing nearly an entire SAR arc surrounding more common green and red aurora, was taken earlier this month from Poolburn, New Zealand, during an especially energeti ...

© Steven Madow

🌌Rocket Transits Rippling Moon Can a rocket make the Moon ripple? No, but it can make a background moon appear wavy. The rocket, in this case, was a SpaceX Falcon Heavy that blasted off from NASA's Kennedy Space Center last week. In the featured launch picture, the rocket's exhaust plume glows beyond its projection onto the distant, rising, and nearly full moon. Oddly, the Moon's lower edge show ...

🌌NGC 1232: A Grand Design Spiral Galaxy Galaxies are fascinating not only for what is visible, but for what is invisible. Grand spiral galaxy NGC 1232, captured in detail by one of the Very Large Telescopes, is a good example. The visible is dominated by millions of bright stars and dark dust, caught up in a gravitational swirl of spiral arms revolving about the center. Open clusters containing ...

🌌Illustris: A Simulation of the Universe How did we get here? Click play, sit back, and watch. A computer simulation of the evolution of the universe provides insight into how galaxies formed and perspectives into humanity's place in the universe. The Illustris project exhausted 20 million CPU hours in 2014 following 12 billion resolution elements spanning a cube 35 million light years on a side ...

© Giacomo Venturin

🌌The Last Full Moon Known to some in the northern hemisphere as December's Cold Moon or the Long Night Moon, the last full moon of 2023 is rising in this surreal mountain and skyscape. The Daliesque scene was captured in a single exposure with a camera and long telephoto lens near Monte Grappa, Italy. The full moon is not melting, though. Its stretched and distorted appearance near the horizon i ...

🌌Shakespeare in Space In 1986, Voyager 2 became the only spacecraft to explore ice giant planet Uranus close up. Still, this newly released image from the NIRCam (Near-Infrared Camera) on the James Webb Space Telescope offers a detailed look at the distant world. The tilted outer planet rotates on its axis once in about 17 hours. Its north pole is presently pointed near our line of sight, offeri ...

© Gaurav Singh

🌌Jupiter and the Geminid For a brief moment, this brilliant fireball meteor outshone Jupiter in planet Earth's night. The serendipitous image was captured while hunting meteors under cold Canadian skies with a camera in timelapse mode on December 14, near the peak of the Geminid meteor shower. The Geminid meteor shower, asteroid 3200 Phaethon's annual gift, always arrives in December. Dust shed ...

© Stefano Pellegrini

🌌Rainbow Aurora over Icelandic Waterfall Yes, but can your aurora do this? First, yes, auroras can look like rainbows even though they are completely different phenomena. Auroras are caused by Sun-created particles being channeled into Earth's atmosphere by Earth's magnetic field, and create colors by exciting atoms at different heights. Conversely, rainbows are created by sunlight backscatterin ...

© David Payne

🌌IC 443: The Jellyfish Nebula Why is this jellyfish swimming in a sea of stars? Drifting near bright star Eta Geminorum, seen at the right, the Jellyfish Nebula extends its tentacles from the bright arcing ridge of emission left of center. In fact, the cosmic jellyfish is part of bubble-shaped supernova remnant IC 443, the expanding debris cloud from a massive star that exploded. Light from the ...

© Valerio Minato

🌌Cathedral, Mountain, Moon Single shots like this require planning. The first step is to realize that such an amazing triple-alignment actually takes place. The second step is to find the best location to photograph it. But it was the third step: being there at exactly the right time -- and when the sky was clear -- that was the hardest. Five times over six years the photographer tried and found ...