Browse NASA Astronomy Picture of the Day archive by date and media: Archive Discoveries
Browse the NASA APOD archive without needing the exact date first. Filter by media type and keep moving deeper into older images and videos.
Phobos: Doomed Moon of Mars
This moon is doomed. Mars , the red planet named for the Roman god of war , has two tiny moons, Phobos and Deimos , whose names are derived from the Greek for Fear and Panic.…
The Seasons of Saturn
Since Saturn's axis is tilted as it orbits the Sun , Saturn has seasons , like those of planet Earth ... but Saturn's seasons last for over seven years. So what season is it on…
Clusters and Nebulae of the Hexagon
At first, the bright stars of the large asterism known as the (northern) Winter Hexagon might be hard to pick out in this gorgeous deep sky mosaic from December 2002. But placing…
Jupiter in the Hive
If you can find planet Jupiter in tonight's sky, then you can also find M44 , popularly known as the Beehive star cluster. In fact, with a pair of binoculars most casual skygazers…
V838 Light Echo: The Movie
What caused this outburst of V838 Mon? For reasons unknown, star V838 Mon 's outer surface suddenly greatly expanded with the result that it became the brightest star in the…
A New Constellation Takes Hold
A new constellation has taken hold of the sky, much to the surprise of many sky gazers . The constellation of Ollie the Owl has suddenly started dominating the southern…
Mt. Etna Lava Plumes
Mt. Etna has been erupting for hundreds of thousands of years. Located in Sicily , Italy , the volcano produces lava fountains over one kilometer high. Mt. Etna is not only one of…
Beijing Ancient Observatory
Did observatories exist before telescopes ? One example that still stands today is the Beijing Ancient Observatory in China . Starting in the 1400s astronomers erected large…
The Shadow of Phobos
Hurtling through space above the Red Planet , potato-shaped Phobos completes an orbit of Mars in less than eight hours. In fact, since its orbital period is shorter than the…
1006 AD: Supernova in the Sky
A new star, likely the brightest supernova in recorded human history , appeared in planet Earth's sky in the year 1006 AD. The expanding debris cloud from the stellar explosion is…
Light Echoes from V838 Mon
Nominated for most mysterious star in the Milky Way, V838 Monocerotis briefly became one of the brightest stars in our galaxy. Its outburst discovered in January 2002,…
A Lenticular Cloud Over Wyoming
Is that a cloud or a flying saucer? Both, although it is surely not an alien spacecraft . Lenticular clouds can be shaped like a saucer, and can fly in the sense that, like most…
A Slow Explosion
Why would a gamma ray burst fade so slowly? This behavior , recorded last October, is considered a new clue into the cause of gamma-ray bursts , the most powerful explosions known…
A Digital Sunset Over Europe and Africa
No single spacecraft or astronaut took this picture . It is a digital composite of archived images taken by several Earth-orbiting satellites and ocean-faring ships. Similar…
Alpha Centauri: The Closest Star System
The closest star system to the Sun is the Alpha Centauri system . Of the three stars in the system, the dimmest -- called Proxima Centauri -- is actually the nearest star . The…
M57: The Ring Nebula
Except for the rings of Saturn , the Ring Nebula (M57) is probably the most famous celestial band. This planetary nebula's simple, graceful appearance is thought to be due to…
Stars and Planets in the Halo of the Moon
Photographed on March 13th from Caledon, Ontario, Canada, a bright Moon was surrounded by this lovely halo. Planet Jupiter and stars Procyon, Castor, and Pollux also appear within…
Sunrise Analemma
Astronomically speaking , at the Equinox on March 21, 0100 UT (March 20, 8:00 PM ET) the season changes. For this Equinox the Sun rises due east as it crosses the celestial…
Jupiter's Great Dark Spot
Seventeenth century astronomer Giovanni Domenico Cassini was an astute observer of Jupiter's Great Red Spot. So it seems only fitting that his namesake, the Cassini spacecraft,…
Coronal Holes on the Sun
The ominous, dark shapes haunting the left side of the Sun are coronal holes -- low density regions extending above the surface where the solar magnetic field opens freely into…
SN 1006: History's Brightest Supernova
Suddenly, in the year 1006 AD, a new star appeared in the sky. Over the course of just a few days, the rogue star became brighter than the planet Venus . The star, likely the talk…
NGC 253: The Sculptor Galaxy
NGC 253 is not only one of the brightest spiral galaxies visible, it is also one of the dustiest . Discovered in 1783 by Caroline Herschel in the constellation of Sculptor , NGC…
Apollo 12: Self-Portrait
Is it art? In November of 1969, Apollo 12 astronaut-photographer Charles “Pete” Conrad recorded this masterpiece while documenting colleague Alan Bean's lunar soil collection…
DEM L71: When Small Stars Explode
Large, massive stars end their furious lives in spectacular supernova explosions -- but small, low mass stars may encounter a similar fate. In fact, instead of simply cooling off…
Viewing discoveries from 6 April 2003 through 14 March 2003.