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.
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…
WISE Infrared Andromeda
This sharp, wide-field view features infrared light from the spiral Andromeda Galaxy (M31) . Dust heated by Andromeda's young stars is shown in yellow and red, while its older…
Vesta Near Opposition
Main belt asteroid 4 Vesta is at its brightest now. The small world is near opposition (opposite the Sun in the sky) and closest to Earth. But even at its brightest, Vesta is just…
An Unusually Smooth Surface on Saturn's Calypso
Why is this moon of Saturn so smooth? This past weekend, humanity's Saturn-orbiting Cassini spacecraft passed as close to Saturn's small moon Calypso as it ever has, and imaged…
Dark Shuttle Approaching
What's that approaching? Astronauts on board the International Space Station first saw it far in the distance. Soon it enlarged to become a dark silhouette . As it came even…
Cassini Spacecraft Crosses Saturn's Ring Plane
If this is Saturn, where are the rings? When Saturn's “appendages” disappeared in 1612, Galileo did not understand why. Later that century, it became understood that Saturn 's…
Field of Rosette
What surrounds the florid Rosette nebula? To better picture this area of the sky, the famous flowery emission nebula on the far right has been captured recently in a deep and…
Waterway to Orbit
The 32nd shuttle mission to the International Space Station, STS-130 , left planet Earth on February 8. Its early morning launch to orbit from Kennedy Space Center's pad 39A…
Teide Sky Trails
The snow capped Teide volcano is reflected in a pool of water in this nearly symmetric night sky view from the Canary Island Tenerife. Bright north star Polaris stands above the…
Star Cluster M34
This pretty , open cluster of stars, M34, is about the size of the Full Moon on the sky. Easy to appreciate in small telescopes, it lies some 1,800 light-years away in the…
Sakurajima Volcano with Lightning
Why does a volcanic eruption sometimes create lightning? Pictured above, the Sakurajima volcano in southern Japan was caught erupting early last month. Magma bubbles so hot they…
Night Launch of the Space Shuttle Endeavour
Sometimes, the space shuttle launches at night. Pictured above , the space shuttle Endeavour lifted off in yesterday's early morning hours from Launch Pad 39A in Kennedy Space…
A Sun Halo Over Cambodia
Have you ever seen a halo around the Sun? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal…
The Einstein Cross Gravitational Lens
Most galaxies have a single nucleus -- does this galaxy have four? The strange answer leads astronomers to conclude that the nucleus of the surrounding galaxy is not even visible…
Hong Kong Sky
This remarkable scene combines multiple exposures recorded on the evening of January 18th from a waterside perspective in Hong Kong, China . It follows a young crescent Moon ,…
Dust Storm on Mars
It's spring for the northern hemisphere of Mars and spring on Mars usually means dust storms . So the dramatic brown swath of dust (top) marking the otherwise white north polar…
Viewing discoveries from 28 February 2010 through 5 February 2010.