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.
Young Martian Terrain
What caused the pits, ridges, and gullies on otherwise smooth Martian terrain? One hypothesis is water. The lack of craters at this mid-latitude location indicates that the…
Oceans Under Jupiter's Callisto?
Why does Jupiter 's moon Callisto alter the magnetic field of Jupiter in its vicinity? Callisto itself does not have a strong magnetic field. One possible answer is that Callisto…
Star Cluster R136 Bursts Out
In the center of star-forming region 30 Doradus lies a huge cluster of the largest, hottest, most massive stars known. Known as R136 , the cluster's energetic stars are breaking…
M57: The Ring Nebula
Except for the rings of Saturn , the Ring Nebula (M57) is probably the most famous celestial band. This planetary nebula's simple, graceful appearance is thought to be due to…
A Daytime Fireball in 1944
While stationed in central Africa in December 1944, Norman Appleton witnessed a meteor so bright he remembered it his entire life. Right before his eyes a tremendous smoking…
Martian Dust Storm
If you've been unhappy with the weather on Earth, check out Mars , now in the grip of a planet-wide dust storm . Above, observations from the orbiting Mars Global Surveyor (MGS)…
Madagascar Totality
When the Moon's shadow reached out and touched Earth's southern hemisphere on 2001 June 21, the first total solar eclipse of the 21st century began. Starting in the Atlantic, the…
Hot Gas Halo Detected Around Galaxy NGC 4631
Is our Milky Way Galaxy surrounded by a halo of hot gas? A step toward solving this long-standing mystery was taken recently with Chandra X-ray observations of nearby galaxy NGC…
The Red Spider Planetary Nebula
Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and…
Atlantis to Orbit
Birds don't fly this high. Airplanes don't go this fast. The Statue of Liberty weighs less. No species other than human can even comprehend what is going on, nor could any human…
NGC 1977: Blue Reflection Nebula in Orion
The Orion Nebula is visible to the unaided eye as a fuzzy patch near the famous belt of three stars in the <a Orion . The above picture captures a part of the Orion Nebula that…
25 Years Ago: Vikings on Mars
On July 20, 1976 , NASA's Viking 1 lander became the first U.S. spacecraft to land on Mars , followed weeks later by its twin robot explorer, the Viking 2 lander. Operating on the…
The Elephant's Trunk in IC 1396
Like a picture from a galactic Just So Story , the Elephant's Trunk Nebula winds through the emission nebula and young star cluster complex IC 1396 , in the high and far off…
Pulsar Wind in the Vela Nebula
The Vela pulsar was born 10,000 years ago at the center of a supernova -- an exploding star . In this Chandra Observatory x-ray image , the pulsar still produces a glowing nebula…
Mars from Earth
Last month, Mars and Earth were right next to each other in their orbits. Formally called opposition , the event was highlighted by a very bright Mars for skywatchers and a good…
The Carina Nebula in Three Colors
Stars, like people, do not always go gentle into that good night . The above Carina Nebula , also known as the Keyhole Nebula and NGC 3372 , results from dying star Eta Carinae's…
Water Found Around Nearby Star CW Leonis
Do worlds outside our Solar System have oceans of water like Earth ? An indication that such worlds might exist was bolstered recently by new evidence that nearby star system CW…
Io in True Color
The strangest moon in the Solar System is bright yellow. This picture , showing Io's true colors, was taken in 1999 July by the Galileo spacecraft currently orbiting Jupiter. Io's…
Solar System Web Cam
Ranging throughout the solar system , these pictures all have something in common. They were taken with an 8 inch diameter telescope, a size popular with amateur astronomy buffs,…
Welcome to the Moon Hotel
The most detailed proposal so far for a hotel and resort destination on the Moon (!) has been prepared by Dutch architect Hans-Jurgen Rombaut. The harsh lunar environment posed…
NGC 1850: Not Found in the Milky Way
A mere 168,000 light-years distant, this large, lovely cluster of stars, NGC 1850 , is located near the outskirts of the central bar structure in our neighboring galaxy, the Large…
A Total Eclipse Over Africa
What's that dark spot on the Sun? It's the Moon. Last month, on June 21, a total solar eclipse was visible in parts of Africa . In one of the most spectacular records of this…
Sudbury Indicates Nonstandard Particle Model
The Sudbury Neutrino Observatory (SNO) has been detecting so few neutrinos from the Sun that the Standard Model of fundamental particles in the universe may have to be revised.…
Air Pollution Earth
Where on Earth is the air most polluted? Recently released images from the Terra satellite show not only areas of high pollution, but also how polluted air moves. In the above…
Viewing discoveries from 1 August 2001 through 9 July 2001.