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.
Sunspot in the Old Solar Cycle
A new cycle has begun on our Sun. Over the past year, the Sun's magnetic field has reset and now a new 11 year period is beginning. Pictured above in a specific color of light…
Three Month Composite of Comet Holmes
How has Comet Holmes changed? Since brightening unexpectedly by nearly one million fold in late October, the last three months have found the coma of Comet 17P/Holmes both…
A Spider Shaped Crater on Mercury
Why does this crater on Mercury look like a spider? When the robotic MESSENGER spacecraft glided by the planet Mercury last month, it was able to image portions of the Sun's…
Light Echoes from V838 Mon
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…
Venus and Jupiter in Morning Skies
These two celestial beacons shining brightly in the east before sunrise are actually children of the Sun , the planets Venus and Jupiter. The second and third brightest objects in…
The First Explorer
Fifty years ago (on January 31, 1958) the First Explorer , was launched into Earth orbit by the Army Ballistic Missile Agency. Inaugurating the era of space exploration for the…
Young Star Cluster Westerlund 2
Dusty stellar nursery RCW 49 surrounds young star cluster Westerlund 2 in this remarkable composite skyscape from beyond the visible spectrum of light. Infrared data from the…
Asteroid 2007 TU24 Passes the Earth
Asteroid 2007 TU24 passed by the Earth yesterday, posing no danger. The space rock, estimated to be about 250 meters across, coasted by just outside the orbit of Earth's Moon. The…
West Valley Panorama from the Spirit Rover on Mars
What does Mars look like from here? Last September, before hiking across rugged and slippery terrain to reach its winter hibernation point, the robotic Spirit rover climbed a…
A Solar Eclipse Painting from the 1700s
Is this painting the earliest realistic depiction of a total eclipse of the Sun? Some historians believe it is. The above painting was completed in 1735 by Cosmas Damian Asam , a…
Mercury on the Horizon
Have you ever seen the planet Mercury? Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth's sky . If trailing the Sun, Mercury will be visible…
Crescent Mercury in Color
Hard to spot against the twilight glow near planet Earth's horizon, a crescent Mercury was imaged close up by the MESSENGER spacecraft early last week. Colors in this remarkable…
Winter Night at Pic du Midi
This dreamlike view looking south from the historic mountain top Pic du Midi Observatory combines moonlit domes, a winter night sky, and the snowy peaks of the French Pyrenees.…
Andromeda Island Universe
The most distant object easily visible to the unaided eye is M31 , the great Andromeda Galaxy some two and a half million light-years away. But without a telescope, even this…
Orbiting Astronaut Reflects Earth
Astronaut self-portraits can be particularly interesting. Visible in the above picture , working in from the outer borders, are the edges of the reflecting helmet of a space suit…
Shelf Cloud Over Saskatchewan
Perhaps it's time to go inside. Such thoughts might occur to people witnessing the approach of an impressive shelf cloud . Shelf clouds are typically seen leading thunderstorms ,…
Mercury's Horizon from MESSENGER
What would it look like to fly past Mercury? Just such an adventure was experienced last week by the MESSENGER spacecraft during its first flyby of the strange moon -like world…
Comet McNaught Over Chile
Comet McNaught was perhaps the most photogenic comet of our time. After making quite a show in the northern hemisphere in early January, the comet moved south and developed a long…
Starry Night Castle
The tantalizing Pleiades star cluster seems to lie just beyond the trees above a dark castle tower in this dramatic view of The World at Night . Recorded earlier this month, the…
Supernova Factory NGC 2770
The stellar explosions known as supernovae are among the most powerful events in the universe. Triggered by the collapsing core of a massive star or the nuclear demise of a white…
Thor's Emerald Helmet
This helmet-shaped cosmic cloud with wing-like appendages is popularly called Thor's Helmet . Heroically sized even for a Norse god , Thor's Helmet is about 30 light-years across.…
MESSENGER Passes Mercury
Two days ago, the MESSENGER spacecraft became only the second spacecraft in human history to swoop past Mercury. The last spacecraft to visit the Sun's closest planet was Mariner…
Double Supernova Remnants DEM L316
Are these two supernova shells related? To help find out, the 8-meter Gemini Telescope located high atop a mountain in Chile was pointed at the unusual, huge, double-lobed cloud…
The Cocoon Nebula from CFHT
What creates the colors of the Cocoon Nebula? The Cocoon Nebula , cataloged as IC 5146, is a strikingly beautiful nebula located about 4,000 light years away toward the…
Viewing discoveries from 6 February 2008 through 14 January 2008.