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.
Illuminated Cloud Trails Above Greece
It may appear to be day, but it's night. Those wondrous orange streaks may appear to be rays from the setting Sun, but they're actually thin clouds illuminated by the Moon as they…
Binary Black Hole in 3C 75
What's happening in the middle of this massive galaxy? There, two bright sources at the center of this composite x-ray (blue)/ radio (pink) image are thought to be co-orbiting…
Centaurus A
Only 11 million light-years away, Centaurus A is the closest active galaxy to planet Earth. Spanning over 60,000 light-years, the peculiar elliptical galaxy, also known as NGC…
JWST: Mirrors and Masked Men
Who are these masked men? Technicians from Ball Aerospace and NASA at Marshall Space Flight Center's X-ray and Cryogenic Facility, of course, testing primary mirror segments of…
Yukon Aurora with Star Trails
Fixed to a tripod, a camera can record graceful trails traced by stars as planet Earth rotates on its axis. But at high latitudes during March and April, it can also capture an…
Saturn's Moon Helene from Cassini
What's happening on the surface of Saturn's moon Helene? The moon was imaged in unprecedented detail last week as the robotic Cassini spacecraft orbiting Saturn swooped to within…
Galaxies Beyond the Heart: Maffei 1 and 2
The two galaxies on the far left were unknown until 1968. Although they would have appeared as two of the brighter galaxies on the night sky, the opaque dust of the central band…
Mars Over the Allalinhorn
What's that bright object in the sky? A common question with answers that vary by time and season , the quick answer just after sunset in middle of last month, from the northern…
Spirit Rover at Engineering Flats on Mars
Is it art? If so, the paintbrush was the Spirit robotic rover , the canvas was the soil on Mars , and the artists were the scientists and engineers of the Mars Exploration Rover…
Pillar at Sunset
Reddened light from the setting Sun illuminates the cloud banks hugging this snowy, rugged terrain. Inspiring a moment of quiet contemplation, the sunset scene included a…
Deep Auriga
The plane of our Milky Way Galaxy runs right through Auriga , the Charioteer . A good part of the ancient northern constellation's rich collection of nebulae and star clusters is…
NGC 4565: Galaxy on Edge
Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours…
The International Space Station from Above
The International Space Station (ISS) is the largest human-made object ever to orbit the Earth . The ISS is so large that it can be seen drifting overhead with the unaided eye ,…
M78 and Reflecting Dust Clouds in Orion
An eerie blue glow and ominous columns of dark dust highlight M78 and other bright reflection nebula in the constellation of Orion . The dark filamentary dust not only absorbs…
Slope Streaks in Acheron Fossae on Mars
What creates these picturesque dark streaks on Mars? No one knows for sure. A leading hypothesis is that streaks like these are caused by fine grained sand sliding down the banks…
Pauli Exclusion Principle: Why You Don't Implode
Why doesn't matter just bunch up? The same principle that keeps neutron stars and white dwarf stars from imploding also keeps people from imploding and makes normal matter mostly…
Dawn's Endeavour
On February 21st, the Space Shuttle Endeavour and the International Space Station (ISS) flew through the sky near dawn over Whitby, Ontario, Canada. Along with star trails, both…
Chasing Carina
A jewel of the southern sky, the Great Carina Nebula , aka NGC 3372, spans over 300 light-years. Near the upper right of this expansive skyscape , it is much larger than the more…
Edge-on Spiral Galaxy NGC 891
This beautiful cosmic portrait features NGC 891 . The spiral galaxy spans about 100 thousand light-years and is seen almost exactly edge-on from our perspective. In fact, about 30…
Astronaut Installs Panoramic Space Window
This space job was almost complete. Floating just below the International Space Station , astronaut Nicholas Patrick put some finishing touches on the newly installed cupola space…
Exceptional Rocket Waves Destroy Sun Dog
What created those rocket waves, and why did they destroy that sun dog? Close inspection of the above image shows not only a rocket rising near the center, but unusual air ripples…
Galaxy Group Hickson 31
Will the result of these galactic collisions be one big elliptical galaxy ? Quite possibly, but not for another billion years. Pictured above , several of the dwarf galaxies of in…
NGC 2440: Cocoon of a New White Dwarf
Like a butterfly , a white dwarf star begins its life by casting off a cocoon that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the…
Geostationary Highway
Put a satellite in a circular orbit about 42,000 kilometers from the center of the Earth (36,000 kilometers or so above the surface) and it will orbit once in 24 hours. Because…
Viewing discoveries from 15 March 2010 through 20 February 2010.