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.
NGC 246 and the Dying Star
Appropriately nicknamed “the Skull Nebula”, planetary nebula NGC 246 really does surround a dying star some 1,600 light-years away in the constellation Cetus . Expelled over a…
Barnard's Loop around the Horsehead Nebula
Why is the Horsehead Nebula surrounded by a bubble? Although glowing like an emission nebula , the origin of the bubble , known as Barnard's Loop , is currently unknown.…
A Solar Prominence from SOHO
How can gas float above the Sun? Twisted magnetic fields arching from the solar surface can trap ionized gas, suspending it in huge looping structures. These majestic plasma…
Galaxy Wars: M81 versus M82
In this stunning cosmic vista , galaxy M81 is on the left surrounded by blue spiral arms. On the right marked by massive gas and dust clouds, is M82 . These two mammoth galaxies…
Smoke from the Cigar Galaxy
Very bright in infrared light , well-known starburst galaxy M82's popular name describes its suggestive shape seen at visible wavelengths - The Cigar Galaxy . Ironically, M82's…
Star Cluster Dreams
Located some 7,000 light-years away toward the constellation Perseus, this pair of open or galactic star clusters really is visible to the unaided eye and was cataloged in 130 BC…
Binary Black Hole in 3C 75
The two bright sources at the center of this composite x-ray (blue)/ radio (pink) image are co-orbiting supermassive black holes powering the giant radio source 3C 75 . Surrounded…
A Sun Halo over Utah
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…
Mars: The View from HiRISE
HiRISE - the High Resolution Imaging Science Experiment - rides on the Mars Reconnaissance Orbiter ( MRO )spacecraft just arrived in Mars orbit on March 10. This sharp view of the…
Molecular Cloud Barnard 68
Where did all the stars go? What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud . Here, a high concentration of dust and molecular…
Vanishing Umbra
During the March 29 total solar eclipse, the Moon's dark central shadow or umbra is vanishing beyond the horizon in this dramatic view of the landscape a few kilometers southeast…
The Crown of the Sun
During a total solar eclipse, the Sun's extensive outer atmosphere or corona is an awesome and inspirational sight. The subtle shades and shimmering features of the corona that…
Unusual Bright Soil on Mars
What is this bright soil on Mars? Several times while rolling across Mars, the treads of the robotic rover Spirit have serendipitously uncovered unusually bright soil. Spirit…
Slightly Beneath Saturn's Ring Plane
When orbiting Saturn, be sure to watch for breathtaking superpositions of moon s, rings , and shadow s. One such picturesque vista was visible recently to the robot Cassini…
A Total Solar Eclipse over Turkey
Some views of last week's total eclipse of the Sun were better than others. One spectacular view occurred over Adrasan (near Antalya ), Turkey and was captured there by…
Stars and Dust Across Corona Australis
A cosmic dust cloud sprawls across a rich field of stars in this gorgeous wide field telescopic vista looking toward Corona Australis , the Southern Crown. Probably less than 500…
A Cosmic Call to Nearby Stars
If you could send a message to an alien civilization , what would you say? The people from the Cosmic Call project sent the above image as the first page of a longer message. The…
Hubble Resolves Expiration Date For Green Cheese Moon
Using the new camera on the Hubble Space Telescope , astronomers have been able to confirm that the Moon is made of green cheese . The telling clue was the resolution of a marked…
Solar Eclipse and SOHO
Neither rain, nor snow, nor dark of night can keep the space-based SOlar Heliospheric Observatory (SOHO) from watching the Sun . In fact, from its vantage point 1.5 million…
When Diamonds Aren't Forever
The track of totality for the first solar eclipse of 2006 began early yesterday on the east coast of Brazil and ended half a world away at sunset in western Mongolia . In between,…
Green and Black Aurora Over Norway
What causes gaps between aurora curtains? These unusual gaps can make auroral displays appear more detailed and intricate. Research using data from four Cluster spacecraft…
Animation of Asteroids Passing Near Earth
How often does an asteroid whiz by the Earth? The above time-lapse animation follows the orbit of the Earth around the Sun for two months in 2002 as numerous asteroids , also…
Moonquakes Surprisingly Common
Why are there so many moonquakes? A recent reanalysis of seismometers left on the moon by the Apollo moon landings has revealed a surprising number of moonquakes occurring within…
Doomed Star Eta Carinae
Eta Carinae may be about to explode. But no one knows when - it may be next year, it may be one million years from now. Eta Carinae 's mass - about 100 times greater than our Sun…
Viewing discoveries from 18 April 2006 through 26 March 2006.