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.
Comet and Aurora Over Alaska
Can you spot the comet? Flowing across the frozen Alaskan landscape is an easily visible, colorful aurora. Just to the lower left, however, well in the background, is something…
The Center of Centaurus A
A fantastic jumble of young blue star clusters, gigantic glowing gas clouds, and imposing dark dust lanes surrounds the central region of the active galaxy Centaurus A. This…
Orion Nebula: The 2MASS View
Few astronomical sights excite the imagination like the nearby stellar nursery known as the Orion Nebula . The Nebula's glowing gas surrounds hot young stars at the edge of an…
The Old Moon in the New Moon's Arms
Also known as the Moon's “ashen glow” or “the old Moon in the new Moon's arms”, Earthshine is Earthlight reflected from the Moon's night side. This dramatic image of Earthshine…
Planets in the West
Have you seen any bright planets lately? Chances are if you've been outside under clear skies just after sunset, then you have. Now shining in the west as bright “ stars ” in the…
The Glory
Looking out the window of an airplane, you might be lucky enough to see “the glory” in the direction directly opposite the Sun. Before airplanes , the phenomenon, known to some as…
Millions of Stars in Omega Centauri
Pictured above is the largest ball of stars in our Galaxy . About 10 million stars orbit the center of this globular cluster - named Omega Centauri - as this giant globular…
A New Truss for the International Space Station
The International Space Station (ISS) is being fitted with a backbone . During the present visit of Space Shuttle Atlantis , astronauts are installing a huge truss on the growing…
RX J185635-375: Candidate Quark Star
Is RJX J185635-375 really so small? Previously, this compact star held claim to being the closest neutron star -- only 150 light-years away. Now new observations and analysis…
Pwyll: Icy Crater of Europa
The impact crater Pwyll (a name from Celtic Mythology ) is thought to represent one of the youngest features on the surface of Jupiter's moon Europa . A combination of color and…
A Galaxy is not a Comet
This gorgeous galaxy and comet portrait was recorded on April 5th in the skies over the Oriental Pyrenees near Figueres, Spain . From a site above 1,100 meters, astrophotographer…
Antennae Galaxies in Near-Infrared
What happens when galaxies collide ? One of the best studied examples of the jumble of star clusters, gas, and dust clouds produced by such a cosmic train wreck is the interacting…
Unusual Rocks in Death Valley
How did those big rocks end up on that strange terrain? One of the more unusual places here on Earth occurs inside Death Valley , California , USA . There a dried lakebed named…
The Snake Nebula from CFHT
What slithers overhead? The dark winding lanes visible in part of the constellation of Ophiuchus belong to the Snake Nebula . Also known as Barnard 72, the Snake Nebula is a…
NGC 2787: A Barred Lenticular Galaxy
Lenticular galaxies aren't supposed to be photogenic. Like spiral galaxies , they contain a disk , but like elliptical galaxies , they are usually short on dust , gas, and pretty…
NGC 2392 from Hubble
In 1787, astronomer William Herschel discovered NGC 2392 . From the ground, NGC 2392 resembles a person's head surrounded by a parka hood. In 2000, the Hubble Space Telescope…
Vintage Gamma Rays
Gamma-rays are the most energetic form of electromagnetic radiation . But these high energy photons penetrate and interact in normal materials and cannot be focused by lenses and…
Gamma-Ray Burst Afterglow: Supernova Connection
What causes the mysterious gamma-ray bursts ? Indicated in this Hubble Space Telescope exposure of an otherwise unremarkable field in the constellation Crater , is the dwindling…
Ikeya-Zhang: Comet Over Colorado
Comet Ikeya-Zhang (“ee-KAY-uh JONG”) has become a most photogenic comet . This lovely early evening view of the comet in Rocky Mountain skies looks northwest over ridges and low…
NGC 4414: A Flocculent Spiral Galaxy
How much mass do flocculent spirals hide? The above true color image of flocculent spiral galaxy NGC 4414 was taken with the Hubble Space Telescope to help answer this question.…
Mysterious Black Water in Florida Bay
What is causing the water in Florida Bay to turn black? The mysterious black color could be seen as early as last December in images taken by the SeaWIFS instrument on board the…
Hubble Resolves Expiration Date For Green Cheese Moon
Using the new camera on the recently refitted Hubble Space Telescope , astronomers have been able to confirm that the Moon is made of green cheese . The telling clue was the…
The Mysterious Rings of Supernova 1987A
What's causing those odd rings in supernova 1987A? In 1987, the brightest supernova in recent history occurred in the Large Magellanic Clouds . At the center of the picture is an…
Venus Unveiled
The surface of Venus is perpetually covered by a veil of thick clouds and remains hidden from even the powerful telescopic eyes of earth-bound astronomers. But in the early 1990s,…
Viewing discoveries from 22 April 2002 through 30 March 2002.