Astronomy Picture of the Day

🌌Edge-On Galaxy NGC 5866 Why is this galaxy so thin? Many disk galaxies are just as thin as NGC 5866, pictured here, but are not seen edge-on from our vantage point. One galaxy that is situated edge-on is our own Milky Way Galaxy. Classified as a lenticular galaxy, NGC 5866 has numerous and complex dust lanes appearing dark and red, while many of the bright stars in the disk give it a more blue ...

© Kevin Sargozza

🌌Venus, Mercury, and the Waning Moon Yesterday, early morning risers around planet Earth were treated to a waning Moon low in the east as the sky grew bright before dawn. From the Island of Ortigia, Syracuse, Sicily, Italy this simple snapshot found the slender sunlit crescent just before sunrise. Never wandering far from the Sun in Earth's sky, inner planets Venus and Mercury shared the calm se ...

© Ignacio Diaz Bobillo

🌌The Tarantula Zone The Tarantula Nebula, also known as 30 Doradus, is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud. About 180 thousand light-years away, it's the largest, most violent star forming region known in the whole Local Group of galaxies. The cosmic arachnid sprawls across the top of this spectacular ...

© Charles Bracken

🌌Comet ATLAS and Orion's Belt With its closest approach to planet Earth scheduled for November 14, this Comet ATLAS (C/2020 M3) was discovered just this summer, another comet found by the NASA funded Asteroid Terrestrial-impact Last Alert System. It won't get as bright as Comet NEOWISE but it can still be spotted using binoculars, as it currently sweeps through the familiar constellation of Orio ...

© Marcella Giulia Pace

🌌Colors of the Moon What color is the Moon? It depends on the night. Outside of the Earth's atmosphere, the dark Moon, which shines by reflected sunlight, appears a magnificently brown-tinged gray. Viewed from inside the Earth's atmosphere, though, the moon can appear quite different. The featured image highlights a collection of apparent colors of the full moon documented by one astrophotograph ...

© Jason Guenzel

🌌The Central Soul Nebula Without Stars This cosmic close-up looks deep inside the Soul Nebula. The dark and brooding dust clouds near the top, outlined by bright ridges of glowing gas, are cataloged as IC 1871. About 25 light-years across, the telescopic field of view spans only a small part of the much larger Heart and Soul nebulae. At an estimated distance of 6,500 light-years the star-forming ...

© Max Rive

🌌In Green Company: Aurora over Norway Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds -- mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display. Arms went high in the air, patience and experience paid off, and the creative featured image was captured as a composi ...

🌌Martian Moon Phobos from Mars Express Why is Phobos so dark? Phobos, the largest and innermost of two Martian moons, is the darkest moon in the entire Solar System. Its unusual orbit and color indicate that it may be a captured asteroid composed of a mixture of ice and dark rock. The featured picture of Phobos near the limb of Mars was captured in 2010 by the robot spacecraft Mars Express curre ...

© Howard Trottier

🌌The Hercules Cluster of Galaxies These are galaxies of the Hercules Cluster, an archipelago of island universes a mere 500 million light-years away. Also known as Abell 2151, this cluster is loaded with gas and dust rich, star-forming spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars. The colors in this deep composite image clea ...

© Derek Demeter

🌌Moon over ISS Completing one orbit of our fair planet in 90 minutes the International Space Station can easily be spotted by eye as a very bright star moving through the night sky. Have you seen it? The next time you do, you will have recognized the location of over 20 years of continuous human presence in space. In fact, the Expedition 1 crew to the ISS docked with the orbital outpost some 400 ...

© Terry Hancock

🌌North of Orion's Belt Bright stars, interstellar clouds of dust and glowing nebulae fill this cosmic scene, a skyscape just north of Orion's belt. Close to the plane of our Milky Way Galaxy, the wide field view spans just under 5 degrees or about 10 full moons on the sky. Striking bluish M78, a reflection nebula, is at the lower right. M78's tint is due to dust preferentially reflecting the blu ...

🌌Fifty Gravitational Wave Events Illustrated Over fifty gravitational wave events have now been detected. These events mark the distant, violent collisions of two black holes, a black hole and a neutron star, or two neutron stars. Most of the 50 events were detected in 2019 by the LIGO gravitational wave detectors in the USA and the VIRGO detector in Europe. In the featured illustration summariz ...

🌌Tagging Bennu: The Movie This is what it looks like to punch an asteroid. Last month, NASA's robotic spacecraft OSIRIS-REx descended toward, thumped into, and then quickly moved away from the small near-Earth asteroid 101955 Bennu. The featured video depicts the Touch-And-Go (TAG) sampling event over a three-hour period. As the movie begins, the automated probe approaches the 500-meter, diamond ...

© Rainee Colacurcio

🌌Half Sun with Prominence What's happening to the Sun? Clearly, the Sun's lower half is hidden behind a thick cloud. Averaging over the entire Earth, clouds block the Sun about 2/3rds of the time, although much less over many land locations. On the Sun's upper right is a prominence of magnetically levitating hot gas. The prominence might seem small but it could easily envelop our Earth and persi ...

🌌In the Center of the Trifid Nebula What's happening at the center of the Trifid Nebula? Three prominent dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear near the bottom, while other dark filaments of dust are visible threaded throughout the nebula. A single massive star visible near the center causes much of the Trifid's glow. The Trifid, cataloged as ...

🌌A Galaxy of Horrors re extreme and terrifying realms of the Universe tonight. If you dare to look, mysterious dark matter, a graveyard galaxy, zombie worlds, and gamma-ray bursts of doom are not all that awaits. Just follow the link and remember, it's all based on real science, even the scary parts. Have a safe and happy halloween! 🔗 https://apod.nasa.gov/apod/ap201031.html

© Dennis Simmons

🌌Fear and Dread: The Moons of Mars On Halloween fear and dread will stalk your night skies, also known as Phobos and Deimos the moons of Mars. The 2020 opposition of Mars was on October 13, so the Red Planet will still rise shortly after sunset. Near Halloween's Full Moon on the sky, its strange yellowish glow will outshine other stars throughout the night. But the two tiny Martian moons are ver ...

© Casey Good/Steve Timmons

🌌The Ghoul of IC 2118 Inspired by the halloween season, this telescopic portrait captures a cosmic cloud with a scary visage. The interstellar scene lies within the dusty expanse of reflection nebula IC 2118 in the constellation Orion. IC 2118 is about 800 light-years from your neighborhood, close to bright bluish star Rigel at the foot of Orion. Often identified as the Witch Head nebula for its ...

© Steven Mohr

🌌NGC 6357: The Lobster Nebula Why is the Lobster Nebula forming some of the most massive stars known? No one is yet sure. Cataloged as NGC 6357, the Lobster Nebula houses the open star cluster Pismis 24 near its center -- a home to unusually bright and massive stars. The overall blue glow near the inner star forming region results from the emission of ionized hydrogen gas. 🔗 https://apod.nasa.g ...

🌌Venusian Volcano Imagined What would an erupting volcano on Venus look like? Evidence of currently active volcanoes on Venus was announced earlier this year with the unexplained warmth of regions thought to contain only ancient volcanoes. Although large scale images of Venus have been taken with radar, thick sulfuric acid clouds would inhibit the taking of optical light vistas. Nevertheless, an ...

© Bogdan Jarzyna

🌌Reflections of the Ghost Nebula Do any shapes seem to jump out at you from this interstellar field of stars and dust? The jeweled expanse, filled with faint, starlight-reflecting clouds, drifts through the night in the royal constellation of Cepheus. Far from your own neighborhood on planet Earth, these ghostly apparitions lurk along the plane of the Milky Way at the edge of the Cepheus Flare m ...

© Tom AbelRalf KaehlerKIPACSLACAMNH

🌌Dark Matter in a Simulated Universe Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters so fast, why gravitational lenses so strongly deflect light, and why visible matter is distributed as it is both in the local universe and on the cosmic microwave bac ...

© Jose Mtanous

🌌Globular Star Cluster 47 Tuc Globular star cluster 47 Tucanae is a jewel of the southern sky. Also known as NGC 104, it roams the halo of our Milky Way Galaxy along with some 200 other globular star clusters. The second brightest globular cluster (after Omega Centauri) as seen from planet Earth, it lies about 13,000 light-years away and can be spotted naked-eye close on the sky to the Small Mag ...

🌌Supernova in NGC 2525 Big, beautiful, barred spiral galaxy NGC 2525 lies 70 million light-years from the Milky Way. It shines in Earth's night sky within the boundaries of the southern constellation Puppis. About 60,000 light-years across, its spiral arms lined with dark dust clouds, massive blue stars, and pinkish starforming regions wind through this gorgeous Hubble Space Telescope snapshot. ...

🌌Tagging Bennu On October 20, after a careful approach to the boulder-strewn surface, the OSIRIS-REx spacecraft's arm reached out and touched asteroid Bennu. Dubbed a Touch-And-Go (TAG) sampling event, the 30 centimeter wide sampling head (TAGSAM) appears to crush some of the rocks in this snapshot. The close-up scene was recorded by the spacecraft's SamCam some 321 million kilometers from plane ...

© Tomáš Slovinský

🌌A Night Sky Vista from Sardinia How many famous sky objects can you find in this image? The featured dark sky composite combines over 60 exposures spanning over 220 degrees to create a veritable menagerie of night sky wonders. Visible celestial icons include the Belt of Orion, the Orion Nebula, the Andromeda Galaxy, the California Nebula, and bright stars Sirius and Betelgeuse. You can verify t ...