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.
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…
The Galactic Center in Infrared
The center of our Galaxy is a busy place. In visible light , much of the Galactic Center is obscured by opaque dust . In infrared light , however, dust glows more and obscures…
A Close Encounter Of The Stellar Kind
The unassuming star centered in this sky view will one day be our next door stellar neighbor. The faint 9th magnitude red dwarf , currently 63 light-years away in the…
Bakasa Eclipse Sequence
Starting at the upper left, this sequence of images follows the progress of the magnificent 21 June, 2001 solar eclipse in the clear skies over Bakasa, Zimbabwe. These pictures…
C/2001 A2 (LINEAR): Comet !
Comet C/2001 A2 (LINEAR) has crossed the celestial equator and is heading north. Outward bound , this primordial piece of the solar system is still just visible to the unaided eye…
Moonbow with Sailboats
Have you ever seen a moonbow? Just as rainbows are lit by the Sun , moonbows are lit by the Moon . Since the Sun is so much brighter than the Moon , sunlit rainbows are much…
Unusual Flashes Toward Globular Cluster M22
What is causing the unusual flashes behind globular cluster M22? This teeming ball of stars is the brightest globular cluster visible from Earth's northern hemisphere. M22 , shown…
The Seasons of Saturn
Soon it will be winter in Saturn's northern hemisphere. Since Saturn is tilted in its orbit around the Sun , it has seasons just like the Earth . When a hemisphere is tilted so…
Viewing discoveries from 25 July 2001 through 2 July 2001.