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.
Galaxies Away
This stunning group of galaxies is far, far away - about 450 million light-years from planet Earth - cataloged as galaxy cluster Abell S0740. Dominated by the cluster's large…
Liquid Lakes on Saturn's Titan
Why would some regions on Titan reflect very little radar? The leading explanation is that these regions are lakes, possibly composed of liquid methane. The above image is a…
Sun Storm: A Coronal Mass Ejection
What's happening to our Sun? Another Coronal Mass Ejection (CME)! The Sun-orbiting SOHO spacecraft has imaged many erupting filaments lifting off the active solar surface and…
Comet Between Fireworks and Lightning
Sometimes the sky itself is the best show in town. On January 26, people from Perth , Australia gathered on a local beach to watch a sky light up with delights near and far.…
Shadow of a Martian Robot
What if you saw your shadow on Mars and it wasn't human ? Then you might be the Opportunity rover currently exploring Mars. Opportunity and sister robot Spirit have been probing…
Alborz Mountains in Moonlight
On January 25th, light from a first quarter Moon illuminated this dreamlike landscape looking across the rugged, snow-covered peaks of the Alborz Mountain Range in northern Iran.…
Flame Nebula Close-Up
Of course, the Flame Nebula is not on fire. Also known as NGC 2024 , the nebula's suggestive reddish color is due to the glow of hydrogen atoms at the edge of the giant Orion…
A Tail of Two Hemispheres
By January 19/20 Comet McNaught's magnificent dust tail stretched for about 150 million kilometers (1 AU), requiring images from both southern and northern hemispheres of planet…
Movie: Cassini Crosses Saturn's Ring Plane
What would the rings of Saturn look like if you passed right through the ring plane? To find out, NASA aimed cameras from the Cassini spacecraft right at Saturn's rings as the…
Thor's Helmet from CFHT
NGC 2359 is a striking emission nebula with an impressive popular name - Thor's Helmet Sure, its suggestive winged appearance might lead some to refer to it as the “ duck nebula”,…
Movie: A Green Flash Over Italy
How could the Sun turn green? Difficult to observe, the momentary green flash above the rising or setting sun has been documented as a phenomenon caused by the atmospheric bending…
Saturn's Hyperion: A Moon with Odd Craters
What lies at the bottom of Hyperion 's strange craters? Nobody knows. To help find out, the robot Cassini spacecraft now orbiting Saturn swooped past the sponge-textured moon in…
Castle and Sky
While Comet McNaught ruled southern skies, last week's conjunction of the Moon and Venus could be enjoyed by denizens of both hemispheres of planet Earth. The two more commonly…
The Star Clusters of NGC 1313
Like grains of sand on a cosmic beach, individual stars of barred spiral galaxy NGC 1313 are resolved in this sharp composite from the Hubble Space Telescope's Advanced Camera for…
Orion's Cradle
Cradled in glowing hydrogen, stellar nurseries in Orion lie at the edge of a giant molecular cloud some 1,500 light-years away. This breath-taking view spans about 13 degrees…
A Comet Tail Horizon
What's happening over the horizon? Many a sky enthusiast who thought they had seen it all had never seen anything like this. To the surprise of many Northern Hemisphere observers,…
The Milky Way Over Paranal
It's not the sky that's falling. More accurately, the Earth is rising. The Earth's rotation gives a continually changing view to all Earth observers, including those measuring the…
The Magnificent Tail of Comet McNaught
Comet McNaught, the Great Comet of 2007, has grown a long and filamentary tail. The spectacular tail spreads across the sky and is visible to Southern Hemisphere observers just…
The Sombrero Galaxy in Infrared
This floating ring is the size of a galaxy. In fact, it is part of the photogenic Sombrero Galaxy , one of the largest galaxies in the nearby Virgo Cluster of Galaxies . The dark…
McNaught's Matinee
Comets grow bright when they're close to the Sun, basking in the intense solar radiation. Of course, they're also usually impossible to see against the overwhelming scattered…
Southern Comet
After a remarkable performance in the northern hemisphere, the brightest comet in decades is now showing off in the south . Recorded during evening twilight on January 17, this…
Comet McNaught from New STEREO Satellite
The brightest comet of recent decades was a surprising first sight for a new camera in space. The Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument…
Kepler's Supernova Remnant in X-Rays
What caused this mess? Some type of star exploded to create the unusually shaped nebula known as Kepler's supernova remnant , but which type? Light from the stellar explosion that…
Comet McNaught Over Catalonia
This past weekend Comet McNaught peaked at a brightness that surpassed even Venus. Fascinated sky enthusiasts in the Earth's northern hemisphere were treated to an instantly…
Viewing discoveries from 8 February 2007 through 15 January 2007.