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.
ULXs in M74
In visual appearance, M74 is a nearly perfect face-on spiral galaxy, about 30 million light-years away toward the constellation Pisces. The red blotches seen in this composite…
Crescents of Titan and Dione
What would it be like to see a sky with many moons? Such is the sky above Saturn . When appearing close to each other, moons will show a similar phase . A view with two of the…
A Tether in Space
One of the greatest unrequited legends of outer space is the tether. Tethers , long strands of material, hold the promise of stabilizing satellites , generating electricity , and…
The Einstein Cross Gravitational Lens
Most galaxies have a single nucleus -- does this galaxy have four? The strange answer leads astronomers to conclude that the nucleus of the surrounding galaxy is not even visible…
Composite Crab
The Crab Pulsar, a city-sized, magnetized neutron star spinning 30 times a second, lies at the center of this composite image of the inner region of the well-known Crab Nebula .…
Huygens Discovers Luna Saturni
In 1655, three hundred fifty years ago on this date, Dutch astronomer Christiaan Huygens discovered Luna Saturni - now known as Saturn's moon Titan. To celebrate, consider this…
Simeis 147: Supernova Remnant
It's easy to get lost following the intricate filaments in this detailed image of faint supernova remnant Simeis 147. Seen towards the constellation Taurus it covers nearly 3…
A Dust Devil Swirling on Mars
What is that wisp on the horizon? Scientists think that the slight white apparition is actually a Martian dust devil that was caught swirling across Mars . The above image was…
To Fly Free in Space
At about 100 meters from the cargo bay of the space shuttle Challenger, Bruce McCandless II was further out than anyone had ever been before. Guided by a Manned Maneuvering Unit…
Orion's Horsehead Nebula
The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the red emission nebula seen above and to the right of center in the…
The Equal Night
Today, the Sun crosses the celestial equator heading north, marking the Vernal Equinox -- the first day of spring in the Northern Hemisphere and autumn in the south . Equinox…
NGC 2266: Old Cluster in the New General Catalog
The New General Catalog of star clusters and nebulae really isn't so new. In fact, it was published in 1888 - an attempt by J. L. E. Dreyer to consolidate the work of astronomers…
Moon, Mercury, Monaco
Low on the western horizon after sunset, a slender crescent Moon and wandering planet Mercury join the lights of Menton and Monaco along the French Riviera. Astronomer Vincent…
Enceladus Close-Up
The surface of Enceladus is as white as fresh snow . Still, an impressive variety of terrain is revealed in this contrast enhanced image. At a resolution of about 30 meters per…
Markarian's Chain of Galaxies
Across the heart of the Virgo Cluster of Galaxies lies a striking string of galaxies known as Markarian's Chain. The chain, pictured above , is highlighted on the upper right with…
Steep Cliffs on Mars
Vertical cliffs of nearly two kilometers occur near the North Pole of Mars. Also visible in the above image of the Martian North Polar Cap are red areas of rock and sand, white…
The Fox Fur Nebula
The nebula surrounding bright star S Mon is filled with dark dust and glowing gas. The strange shapes originate from fine interstellar dust reacting in complex ways with the…
A Message From Earth
What are these Earthlings trying to tell us? The above message was broadcast from Earth towards the globular star cluster M13 in 1974. During the dedication of the Arecibo…
Accretion Disk Simulation
Don't be fooled by the familiar pattern. The graceful spiral structure seen in this computer visualization does not portray winding spiral arms in a distant galaxy of stars .…
Infrared Ring Nebula
The classic appearance of the popular Ring Nebula (aka M57) is understood to be due to perspective - our view from planet Earth looks down the center of a roughly barrel-shaped…
NGC 1499: California Nebula
Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States. Our own Sun…
A Sun Halo Over Tennessee
Sometimes it looks like the Sun is being viewed through a large lens . In the above case, however, there are actually millions of lenses: ice crystals . As water freezes in the…
Crater on Mimas
Whatever hit Mimas nearly destroyed it. What remains is one of the largest impact craters on one of Saturn 's smallest moons. The crater, named Herschel after the 1789 discoverer…
Mercury Over Leeds
Have you ever seen the planet Mercury? This week might be a good time. Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth's sky. If trailing…
Viewing discoveries from 30 March 2005 through 7 March 2005.