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.
Sedimentary Mars
High-resolution imaging of an area in the Schiaparelli Basin of Mars on June 3 by the MGS Mars Orbiter camera produced this stunning example of layered formations within an old…
Dark Matter Map
The total mass within giant galaxy cluster CL0025+1654 , about 4.5 billion light-years away , produces a cosmic gravitational lens -- bending light as predicted by Einstein's…
Mars Rising Behind Poodle Rock
Have you seen Mars lately? As Earth and Mars near their closest approach in nearly 60,000 years on August 27, the red planet has begun to appear dramatically bright and show…
X-Rays from Stephan's Quintet
Stephan's Quintet is a picturesque but clearly troubled grouping of galaxies about 300 million light-years away toward the high-flying constellation Pegasus . Spanning over…
Elements of the Swan Nebula
In the depths of the dark clouds of dust and molecular gas known as M17 , stars continue to form. Also known as the Omega Nebula and Horseshoe Nebula, the darkness of M17's…
Lunation
Our Moon's appearance changes nightly. This time-lapse sequence shows what our Moon looks like during a lunation , a complete lunar cycle. As the Moon orbits the Earth , the half…
A Perseid Aurora
Just after the Moon set but before the Sun rose in the early morning hours of 2000 August 12, meteors pelted the Earth from the direction of the constellation Perseus , while ions…
Blue Stragglers in NGC 6397
In our neck of the Galaxy stars are too far apart to be in danger of colliding, but in the dense cores of globular star clusters star collisions may be relatively common. In fact,…
Palomar at Night
What's wrong with this picture? The summer night sky is clear, and moonlight illuminates the dome of the Hale 200-inch Telescope at Palomar Observatory , northeast of San Diego,…
Dusty Galaxy Centaurus A
Why is peculiar galaxy Centaurus A so dusty? Dramatic dust lanes that run across the galaxy's center mark Cen A . These dust lanes are so thick they almost completely obscure the…
Shuttle Ferry
How does a space shuttle that landed in California get back to Florida for its next launch ? The answer is by ferry. NASA operates two commercial Boeing 747 airplanes modified to…
In the Center of the Virgo Cluster
The Virgo Cluster of Galaxies is the closest cluster of galaxies to our Milky Way Galaxy . The Virgo Cluster is so close that it spans more than 5 degrees on the sky - about 10…
Ice Fishing for Cosmic Neutrinos
Scientists are melting holes in the bottom of the world. In fact, several holes have been melted near the South Pole , and they are now being used as astronomical observatories.…
Island Universe, Cosmic Sand
On August 13, 2002, while counting Perseid meteors under dark , early morning Arizona skies, Rick Scott set out to photograph their fleeting but fiery trails. The equipment he…
Moons and Bright Mars
In this serene view , the moons of Earth along with the bright planet Mars shine above the city of Turku near the southwestern tip of Finland. Of course Earth's large natural…
Galaxy Group HCG 87
Posing for this cosmic family photo are the galaxies of HCG ( Hickson Compact Group ) 87, about four hundred million light-years distant toward the amphibious constellation…
Frosty Mountains on Mars
What causes the unusual white color on some Martian mountains? The answer can be guessed by noticing that the bright areas disappear as springtime takes hold in the south of Mars:…
Orange Sun Simmering
Even a quiet Sun is a busy place. The above image , taken in a single color of light called Hydrogen Alpha , records a great amount of detail of the simmering surface of our…
Launch of the Spirit Rover Toward Mars
Next stop: Mars . Last month the first of two missions to Mars was launched from Cape Canaveral , Florida , USA above a Boeing Delta II rocket . Pictured above, solid fuel…
The Aquarius Dwarf
Our Milky Way Galaxy is not alone. It is part of a gathering of about 50 galaxies known as the Local Group . Members include the Great Andromeda Galaxy (M31), M32 , M33 , the…
Spiral Galaxy NGC 7742
This might resemble a fried egg you've had for breakfast , but it's actually much larger. In fact, ringed by blue-tinted star forming regions and faintly visible spiral arms , the…
Dumbbell Nebula Halo
In 1764, French astronomer Charles Messier sighted this gorgeous cosmic cloud which he described as an oval nebula without stars. Cataloged as M27 , it is now popularly known as…
Mars at the Moon's Edge
What was that bright “star” near the Moon last week? Mars of course, as the Red Planet wandered near the waning gibbous Moon early last Thursday morning, passing behind the lunar…
GRACE Maps the Gravity of Earth
Why do some places on Earth have higher gravity than others? Sometimes the reason is unknown. To help better understand the Earth's surface , slight distance changes between a…
Viewing discoveries from 15 August 2003 through 23 July 2003.