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.
Io's Giant Volcano Pele
Explanation : Io has some very large volcanoes. One of the largest is evident near the center of the above photograph and named Pele , for the mythological Polynesian fire…
Ice at the Lunar South Pole
Explanation : Ice on the Moon? The prospecting Clementine spacecraft may well have discovered it. In 1994, Clementine spent 70 days in lunar orbit mapping the Moon's surface .…
Cocoon of a New White Dwarf
Explanation : 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…
Orion's Star Colors
Explanation : What determines a star's color? Its temperature . Red stars are cool, with temperatures of around 3,000 kelvins (K), while blue stars are hotter and can have…
Star Trails in Northern Skies
Explanation : As the Earth spins on its axis, the sky seems to rotate around us . This motion produces the beautiful concentric arcs traced out by the stars in this time exposure…
Aurora Astern
Explanation : Sailing upside down , 115 nautical miles above Earth, the crew of the Space Shuttle Endeavour made this spectacular time exposure of the southern aurora (aurora…
Io: The Fissure King?
Explanation : Is Io the solar system's Fissure King ? Well, probably not ... but it is the most active volcanic moon . Active volcanoes on Jupiter's moon Io were a surprise…
Comet-like Clouds in the Cartwheel Galaxy
Explanation : In a cartwheel-shaped galaxy far, far away, huge comet-shaped clouds of gas have been discovered racing through the nucleus at about 700,000 miles per hour. The…
Storm Clouds Over Jupiter
Explanation : Storm clouds , similar to the familiar cumulonimbus thunderheads of Earth , appear to be present on Jupiter. The mosaic of images above shows the region near the…
The Radio Sky: Tuned to 408MHz
Explanation : Tune your radio telescope to 408MHz (408 million cycles per second) and check out the Radio Sky! You should find that frequency on your dial somewhere between US…
A Quasar Portrait Gallery
Explanation : QUASARs (QUASi-stellAR objects) lie near the edge of the observable Universe . Discovered in 1963 , astronomers were astounded - to be visible at such extreme…
Apollo 12 Visits Surveyor 3
Explanation : Apollo 12 was the second mission to land humans on the Moon . The landing site was picked to be near the location of Surveyor 3, a robot spacecraft that had landed…
Gamma Ray Bursts from the Unknown
Explanation : Gamma Ray Bursts (GRBs) pose one of the greatest mysteries of modern astronomy. About once a day, the gamma-ray sky lights up with a spectacular explosion. No one…
Fliers Around the Blue Snowball Nebula
Explanation : Planetary nebulae are strange. First, they are gas clouds and have nothing to do with our Solar System 's planets. Next, although hundreds of planetary nebulae have…
The Blue Snowball Planetary Nebula
Explanation : Will the Sun one day look like - a blue snowball? Maybe! The Blue Snowball is a planetary nebula - and in 5 billion years the Sun will throw off its outer layers and…
Europa Full Face
Explanation : What mysteries might be solved by peering into this crystal ball? This crystal ball is quite unusual because it is actually a moon of Jupiter , the crystals are…
Fractal Interstellar Dust Up-Close
Explanation : Our universe is a very dusty place. Dust usually shows its presence by blocking out light emitted from stars or nebula behind it, sometimes creating the illusion of…
Unusual M82: The Cigar Galaxy
Explanation : Something strange happened to this galaxy, but what? M82 is a nearby galaxy in the group of galaxies dominated by itself, M81 , and NGC 3077 . M82 is thought by some…
A Quasar in the Gamma-Ray Sky
Explanation : The bright object in the center of the false color image above is quasar 3C279 viewed in gamma-rays , photons with more than 40 million times the energy of visible…
The Leonid Meteor Shower (Tonight)
Explanation : Tonight thousands of icy rocks will hurl toward Earth in a fascinating display of light called the Leonid Meteor Shower . There is little danger - few will reach the…
Searching For Solar Systems
Explanation : Observational astronomy has recently provided evidence of the existence of massive Jupiter-sized planets orbiting distant suns, protoplanetary disks of gas and dust…
Supernova Remnant and Neutron Star
Explanation : A massive star ends life as a supernova, blasting its outer layers back to interstellar space. The spectacular death explosion is initiated by the collapse of what…
Seven Jets from Comet Hale-Bopp
Explanation : Comet Hale-Bopp is turning out to be quite unusual. One reason is the great amount of jet activity at such a large distance from the Sun . In the above false-color…
Comet Hale-Bopp Passes M14
Explanation : Comet Hale-Bopp continues its slow trek across the night sky, and can now be seen superposed near the bright globular cluster M14 . Will Comet Hale-Bopp become as…
Viewing discoveries from 5 December 1996 through 12 November 1996.