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.
Sandy Gas Jets Hypothesized on Mars
What's causing seasonal dark spots on Mars? Every spring, strange dark spots appear near the Martian poles, and then vanish a few months later. These spots typically span 50…
A Smoke Angel from Airplane Flares
What type of cloud is that? It is not a naturally occurring one. Looking perhaps a bit like a gigantic owl monster, the cloud pictured above resulted from a series of flares…
Ceres: Asteroid or Planet?
Is Ceres an asteroid or a planet? Although a trivial designation to some, the recent suggestion by the Planet Definition Committee of the International Astronomical Union would…
A Map of Asteroid Vesta
Vesta is a huge rock 500 kilometers across that orbits out past Mars . In 1997, the above map of Vesta created using the Hubble Space Telescope was released showing a rugged…
Ceci n'est pas un Meteore
To paraphrase Magritte , “This is not a meteor”. It's not a picture of a meteor either, but it was taken during last weekend's peak of the Perseid Meteor shower. Skywatching with…
Spitzer's Orion
Few cosmic vistas excite the imagination like the Orion Nebula , an immense stellar nursery some 1,500 light-years away. Also known as M42, the nebula is visible to the unaided…
Comet Dust over Colorado
The rock formation in the foreground of this night view was recorded on August 10, illuminated by light from a waning gibbous Moon. Even though the sky above also scatters the…
The North America and Pelican Nebulas
Here are some familiar shapes in unfamiliar locations. This emission nebula on the left is famous partly because it resembles Earth's continent of North America. To the right of…
IC 410 and NGC 1893
A faint, dusty rose of the northern sky, emission nebula IC 410 lies about 12,000 light-years away in the constellation Auriga . The cloud of glowing hydrogen gas is over 100…
Cosmic Rays
Have you ever been hit by a beam of high energy particles from above? Surely you have -- it happens all of the time. Showers of high energy particles occur when energetic cosmic…
The Comet and the Galaxy
The Moon almost ruined this photograph. During late March and early April 1997, Comet Hale-Bopp passed nearly in front of the Andromeda Galaxy . Here the Great Comet of 1997 and…
The First Explorer
Inaugurating the era of space exploration for the US, the First Explorer , a thirty pound satellite, was launched into Earth orbit on January 31, 1958 by the Army Ballistic…
Perseid in the Light
Dark skies are favored for viewing meteor showers -- so many are pessimistic about this year's Perseids. While the Perseid meteor shower is scheduled to peak this weekend, bright…
Galactic Center Star Clusters
If you had x-ray vision , the central regions of our Galaxy would not be hidden from view by cosmic dust clouds. Instead , the Milky Way toward Sagittarius might look something…
Magellanic Morning
This early morning skyscape recorded near Winton, Queensland, Australia, looks toward the southeast. Low clouds are seen in silhouette against the first hints of sunlight, while…
Horse Head Shaped Reflection Nebula IC 4592
Do you see the horse's head? What you are seeing is not the famous Horsehead nebula toward Orion but rather a fainter nebula that only takes on a familiar form with deeper…
An Erupting Solar Prominence from SOHO
Our Sun is still very active. In the year 2000, our Sun went though Solar Maximum , the time in its 11-year cycle where the most sunspots and explosive activities occur. Sunspots…
A Cerro Tololo Sky
High atop a Chilean mountain lies one of the premier observatories of the southern sky: the Cerro Tololo Inter-American Observatory (CTIO). Pictured above is the dome surrounding…
Still Life with NGC 2170
In this beautiful celestial still life composed with a cosmic brush, dusty nebula NGC 2170 shines at the upper left. Reflecting the light of nearby hot stars, NGC 2170 is joined…
Burns Cliff Anaglyph
Get out your red/blue glasses and gaze across Burns Cliff along the inner wall of Endurance crater on Mars! The view from the perspective of Mars rover Opportunity is a color…
M27: Not A Comet
While searching the skies above 18th century France for comets, astronomer Charles Messier diligently recorded this object as number 27 on his list of things which are definitely…
Methane Rain Possible on Titan
Might it rain cold methane on Saturn's Titan? Recent analyses of measurements taken by the Huygen's probe that landed on Titan in 2005 January indicate that the atmosphere is…
The Milky Way over Utah
If sometimes it appears that the entire Milky Way Galaxy is raining down on your head, do not despair. It happens twice a day. As the Sun rises in the East, wonders of the night…
Possible Methane Lakes on Titan
Have methane lakes been discovered on Saturn's Titan? That exciting possibility was uncovered from analyses of radar images returned last week by the robotic Cassini spacecraft…
Viewing discoveries from 23 August 2006 through 31 July 2006.