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.

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…

A Tornado on Planet Earth
Large storms on Earth can spawn unusual, small, violent clouds known as tornadoes. Tornado clouds swirl as fast as hundreds of kilometers per hour and, when they touch down, can…

IC 4603: Reflection Nebula in Ophiuchius
Why does this starfield photograph resemble an impressionistic painting ? The effect is created not by digital trickery but by large amounts of interstellar dust . Dust, minute…

An Ion Drive for Deep Space 1
Space travel entered the age of the ion drive in 1998 with the launch of Deep Space 1 , a NASA mission designed primarily to test new technologies. Although the ion drive on Deep…

NGC 3621: Far Beyond the Local Group
Far beyond the local group of galaxies lies NGC 3621 , some 22 million light-years away. Found in the serpentine southern constellation Hydra , the loose spiral arms of this…

The Planet, the White Dwarf, and the Neutron Star
A planet , a white dwarf , and a neutron star orbit each other in the giant globular star cluster M4 , some 5,600 light-years away. The most visible member of the trio is the…

The Cat's Paw Nebula
As soon as we find out whose cat did this . . . Nebulae are as famous for being identified with familiar shapes as perhaps cats are for getting into trouble. No cat, though, could…

Mars' Simulated View
When earthdweller Patrick Vantuyne wondered what his home planet's single large moon would look like if viewed from Mars on July 17, he availed himself of the JPL Solar System…
Viewing discoveries from 8 August 2003 through 16 July 2003.