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.
Jets from SS433
Explanation : SS433 is one of the most exotic star systems known. Its unremarkable name stems from its inclusion in a catalog of stars which emit radiation characteristic of…
Arecibo: The Largest Telescope
Explanation : The Arecibo radio telescope is currently the largest single-dish telescope in the world. First opening in 1963, this 305 meter (1000 foot) radio telescope resides in…
The Sun Puffs
Explanation : The Earth has once again endured a burst of particles from the Sun. The latest storm , which began Monday, was one of the best documented solar storms to date. At 10…
Europa's Ice Rafts
Explanation : The surface of Jupiter 's moon Europa has shifted. Photographs released yesterday of Europa's surface taken by the spacecraft Galileo show that the smooth moon's icy…
Oceans Under Jupiter's Europa?
Explanation : Is there life beneath Europa? Today, new results are being announced (at about 2 pm EST) about the possibility of oceans under Jupiter 's moon Europa . The existence…
Comet Hale-Bopp Over New York City
Explanation : What's that point of light above the World Trade Center ? It's Comet Hale-Bopp ! Both faster than a speeding bullet and able to “leap” tall buildings in its single…
GRB970228: What's There?
Explanation : Could this fuzzy blob be the key to the whole gamma-ray burst (GRB) mystery ? Astronomers the world over are now scrambling to determine the true nature of the…
Mercury Astronauts and a Redstone
Explanation : Space suited project Mercury astronauts John H. Glenn , Virgil I. Grissom , and Alan B. Shepard Jr. (left to right) are pictured here posing in front of a Redstone…
A Black Hole in M87?
Explanation : The center of nearby giant galaxy M87 is a dense and violent place. In this 1994 photograph by the Hubble Space Telescope , a disk of hot gas was found to be…
Hale-Bopp in Stereo
Explanation : This stereo pair of Hale-Bopp images combines two pictures from slightly different viewing angles. Simulating stereo vision , the difference was generated by the…
Earth, Clouds, Sky, Comet
Explanation : Does a comet's dust tail always orbit behind it? Since comets rotate, they shed gas and dust in all directions equally. Small ice and dust particles expelled by the…
A Complete Aurora
Explanation : Aurora frequently make complete rings around a pole of the Earth. This particular “ crown ”, visible in orange near the top of this image , was taken by the orbiting…
Hale-Bopp and Andromeda
Explanation : Which is closer: the comet or the galaxy? Answer: the comet. In its trek through the inner Solar System , Comet Hale-Bopp has passed nearly in front of the Andromeda…
NGC 3242: The 'Ghost of Jupiter' Planetary Nebula
Explanation : It's a weed , it's Jupiter , no it's - actually planetary nebula NGC 3242. After a star like our Sun completes fusion in its core, it throws off its outer layers it…
Dusty Galaxy Centaurus A
Explanation : One of the most unusual galaxies known , Centaurus A , is pictured above. Cen A is marked by dramatic dust lanes that run across the galaxy's center. These dust…
The Closest Galaxy: The Sagittarius Dwarf
Explanation : What's the closest galaxy to our Milky Way ? For many years astronomers thought it was the Large Magellanic Cloud (LMC). But the seemingly insignificant fuzzy patch…
A Comet In The Sky
Explanation : It has been suggested that Comet Hale-Bopp will become the most viewed comet in Human history . Presently, for denizens of the Earth's northern hemisphere, this…
Comet Country
Explanation : Moonlight illuminates the landscape and lends a painterly quality to this beautiful photograph of the Absaroka mountain range , located along the Montana-Wyoming…
The City Comet
Explanation : Undaunted by the artificial glow from one of the most famous urban skylines on Earth, comet Hale-Bopp shines above the city of New York, USA . Photographed on March…
Hale-Bopp Brightest Comet This Century
Explanation : A comet as bright as Comet Hale-Bopp is very rare indeed. No comet has emitted or reflected this much light since possibly the Great Comet of 1811 . However, since…
The Weather on Mars
Explanation : Would Mars be a nice place to visit? Sometimes. Much of Mars undergoes severe changes in climate during its orbit around the Sun, ranging from extreme cold to…
A String Of Pearls
Explanation : Comet Shoemaker-Levy 9 , named after its co-discoverers , was often referred to as the “string of pearls” comet. It is famous for its unusual appearance as well as…
M64: The Sleeping Beauty Galaxy
Explanation : The Sleeping Beauty galaxy may appear peaceful at first sight but it is actually tossing and turning. In an unexpected twist, recent observations have shown that the…
Io's Surface: Under Construction
Explanation : Like the downtown area of your favorite city, the roads you drive to work on, and any self-respecting Web site ... Io's surface is constantly under construction .…
Viewing discoveries from 13 April 1997 through 21 March 1997.