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.
Shelf Cloud Over Saskatchewan
Perhaps it's time to go inside. Such thoughts might occur to people witnessing the approach of an impressive shelf cloud . Shelf clouds are typically seen leading thunderstorms ,…
Mercury's Horizon from MESSENGER
What would it look like to fly past Mercury? Just such an adventure was experienced last week by the MESSENGER spacecraft during its first flyby of the strange moon -like world…
Comet McNaught Over Chile
Comet McNaught was perhaps the most photogenic comet of our time. After making quite a show in the northern hemisphere in early January, the comet moved south and developed a long…
Starry Night Castle
The tantalizing Pleiades star cluster seems to lie just beyond the trees above a dark castle tower in this dramatic view of The World at Night . Recorded earlier this month, the…
Supernova Factory NGC 2770
The stellar explosions known as supernovae are among the most powerful events in the universe. Triggered by the collapsing core of a massive star or the nuclear demise of a white…
Thor's Emerald Helmet
This helmet-shaped cosmic cloud with wing-like appendages is popularly called Thor's Helmet . Heroically sized even for a Norse god , Thor's Helmet is about 30 light-years across.…
MESSENGER Passes Mercury
Two days ago, the MESSENGER spacecraft became only the second spacecraft in human history to swoop past Mercury. The last spacecraft to visit the Sun's closest planet was Mariner…
Double Supernova Remnants DEM L316
Are these two supernova shells related? To help find out, the 8-meter Gemini Telescope located high atop a mountain in Chile was pointed at the unusual, huge, double-lobed cloud…
The Cocoon Nebula from CFHT
What creates the colors of the Cocoon Nebula? The Cocoon Nebula , cataloged as IC 5146, is a strikingly beautiful nebula located about 4,000 light years away toward the…
Hurricane Ivan from the Space Station
Ninety percent of the houses on Grenada were damaged by the destructive force of Hurricane Ivan . At its peak, Ivan was a Category 5 hurricane , the highest power category on the…
Mercury Chases the Sunset
This colorful view of the western sky at sunset features last Wednesday's slender crescent Moon. Of course, when the Moon is in its crescent phase it can never be far from the Sun…
Polaris Dust Nebula
Centered on North Star Polaris , this 4 degree wide field of view covers part of a complex of relatively unfamiliar , diffuse dust clouds soaring high above the plane of our Milky…
Active Galaxy Centaurus A
A mere 11 million light-years away, Centaurus A is a giant elliptical galaxy - the closest active galaxy to Earth. This remarkable composite view of the galaxy combines image data…
Hidden Galaxy IC 342 from Kitt Peak
Beautiful nearby spiral galaxy IC 342 could be more famous if it wasn't so hidden. A sprawling island universe , IC 342 would be a prominent galaxy in our night sky , but it is…
A Jupiter-Io Montage from New Horizons
As the New Horizons spacecraft sweeps through the Solar System, it is taking breathtaking images of the planets. In February of last year, New Horizons passed Jupiter and the…
Quadrantid Meteors and Aurora from the Air
Where do meteor showers originate? To help answer this question, astronomers studied in some detail the Quadrantid meteor shower that occurred over this past weekend. In…
Jupiter's Rings Revealed
Why does Jupiter have rings? Jupiter's rings were discovered in 1979 by the passing Voyager 1 spacecraft , but their origin was a mystery. Data from the Galileo spacecraft that…
M51: Cosmic Whirlpool
Follow the handle of the Big Dipper away from the dipper's bowl, until you get to the handle's last bright star. Then, just slide your telescope a little south and west and you…
The Milky Way at 5000 Meters
Climb up to 5000 meters (16,500 feet) above sea level, near Cerro Chajnantor in the northern Chilean Andes , and your night sky could encompass this cosmic vista. Recorded from…
Geminids in 2007
Dust from curious near-Earth asteroid 3200 Phaethon seems to fall from the constellation Gemini in this fisheye skyview. The composite image was recorded over four December nights…
A Galaxy is not a Comet
This gorgeous galaxy and comet portrait was recorded on December 30th, in the skies over Hoogeveen, The Netherlands. The combined series of 60 x 60 second exposures finds the…
Rays from an Unexpected Aurora
This aurora was a bit of a surprise. For starters, on this day in 2002, no intense auroral activity was expected at all. Possibly more surprising, however, the aurora appeared to…
A Year of Spectacular Comets
Two spectacular comets graced Earth's skies during 2007. Both comets became bright enough to be seen by the unaided eye of the casual sky enthusiast . Early in 2007, Comet…
Mammatus Clouds Over Mexico
Normal cloud bottoms are flat because moist warm air that rises and cools will condense into water droplets at a very specific temperature, which usually corresponds to a very…
Viewing discoveries from 22 January 2008 through 30 December 2007.