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.
The Powerful Sumatra-Andaman Islands Earthquake
December's 9.0 earthquake has likely shortened Earth's day by about three microsecond s and may also have tweaked Earth's rotational wobble . The megathrust earthquake occurred as…
NGC 1531/2: Interacting Galaxies
This dramatic image of an interacting pair of galaxies was made using 8-meter Gemini South telescope at Cerro Pachon , Chile . NGC 1531 is the background galaxy with a bright core…
Unusual Plates on Mars
What are those unusual plates on Mars? A leading current interpretation holds that they are blocks of ice floating on a recently frozen sea covered by dust. The unusual plates…
The Solar Spectrum
It is still not known why the Sun's light is missing some colors. Shown above are all the visible colors of the Sun , produced by passing the Sun's light through a prism -like…
Frizion Illume
Scientific images of cosmic dust clouds or even frozen water can be esthetic too. In fact, this picture of thin layers of forming ice crystals uses a scientific understanding of…
Saturn's Dragon Storm
Dubbed the “Dragon Storm” , convoluted, swirling cloud features are tinted orange in this false-color, near-infrared image of Saturn's southern hemisphere. In one of a series of…
Ski Enceladus
Small, icy, inner moon of Saturn , Enceladus is only about 500 kilometers in diameter. But the distant world does reflect over 90 percent of the sunlight it receives, giving its…
Voyage of an Antarctic Iceberg
What if part of New York broke off and slammed into New Jersey ? Both being anchored land masses , that is unlikely to happen, but an event of that size scale did occur off the…
Persistent Saturnian Auroras
Are Saturn's auroras like Earth's? To help answer this question, the Hubble Space Telescope and the Cassini spacecraft monitored Saturn's South Pole simultaneously as Cassini…
Galactic Magnetar Throws Giant Flare
Was the brightest Galactic blast yet recorded a key to connecting two types of celestial explosions? Last December, a dense sheet of gamma rays only a few times wider than the…
Oklo: Ancient African Nuclear Reactors
The remnants of nuclear reactors nearly two billion years old were found in the 1970s in Africa. These reactors are thought to have occurred naturally. No natural reactors exist…
Saturnian Aurora
Saturn's Rings are one of the most spectacular sights in the solar system. Still, this image from the Hubble Space Telescope offers a striking view of another kind of ring around…
Big Dipper Castle
The stars of the big dipper, a well known asterism in the constellation Ursa Major , are easy to recognize in this dramatic skyscape . In fact, northern hemisphere skygazers often…
Melas, Candor, and Ophir: Valleys of Mariner
First imaged by the Mariner 9 spacecraft, Valles Marineris , the grand canyon of Mars , is a system of enormous depressions or chasmas that stretch some 4,000 kilometers along the…
Sunspot Metamorphosis: From Bottom to Top
Sunspots -- magnets the size of the Earth -- are normally seen flat on the Sun. The above digital metamorphosis, however, shows a sunspot as it appears at increasing heights,…
Saturn's Moon Rhea from Cassini
Each moon of Saturn seems to come with its own mystery . Rhea, Saturn's second largest moon behind Titan , shows unusual wisps, visible above as light colored streaks. Higher…
The Rosette Nebula
Would the Rosette Nebula by any other name look as sweet ? The bland New General Catalog designation of NGC 2237 doesn't appear to diminish the appearance of the this flowery…
In the Center of the Virgo Cluster
The Virgo Cluster of Galaxies is the closest cluster of galaxies to our Milky Way Galaxy . The Virgo Cluster is so close that it spans more than 5 degrees on the sky - about 10…
NEAR at Eros: Before Touchdown
On 12 February, 2001, the NEAR-Shoemaker spacecraft gently touched-down on the surface of Eros -- the first ever landing on an asteroid . During the descent, the spacecraft's…
Blue Saturn
Serene blue hues highlight this view of Saturn's northern hemisphere from the Cassini spacecraft. The image has been adjusted to approximate the natural blue color of visible…
Red Saturn
This strange, false-color image of otherwise familiar planet Saturn shows temperature changes based on thermal infrared emission in the gas giant's atmosphere and rings. Recorded…
Heat Shield Impact Crater on Mars
Broken metal and scorched Mars make the impact site of Opportunity's heat shield one of the more interesting sites inspected by the rolling robot . Visible on the image left is…
A Mysterious Streak Above Hawaii
What in heavens-above was that? Not everything seen on the night sky is understood. The Night Sky Live (NSL) project keeps its global array of continuously updating web cameras…
A Telescope Laser Creates an Artificial Star
What do you get when you combine one of the world's most powerful telescopes with a powerful laser ? An artificial star. Monitoring fluctuations in brightness of a genuine bright…
Viewing discoveries from 2 March 2005 through 7 February 2005.