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.
Io: The Prometheus Plume
Two sulfurous eruptions are visible on Jupiter's volcanic moon Io in this color composite Galileo image . On the left, over Io's limb, a new bluish plume rises about 86 miles…
Zimbabwe Sunset
Today's scheduled geocentric astronomical event is the Solstice , with the Sun reaching its northernmost declination at 13 hours 24 minutes Universal Time . For denizens of planet…
Bright Galaxy M81
Big and beautiful spiral galaxy M81 , in the northern constellation Ursa Major , is one of the brightest galaxies visible in the skies of planet Earth. This superbly detailed view…
The Moon & Venus Over Geneva
The Moon, fresh from a biting encounter with the Sun last week , appeared next to threaten Venus. The waxing Moon appeared to glide right past, however, just a few degrees away .…
IC 4406: A Seemingly Square Nebula
How can a round star make a square nebula? This conundrum comes to light when studying planetary nebulae like IC 4406. Evidence indicates that IC 4406 is likely a hollow cylinder,…
NGC 4697: X-Rays from an Elliptical Galaxy
The many bright, point-like sources in this Chandra Observatory x-ray image lie within NGC 4697, an elliptical galaxy some 40 million light-years away towards Virgo . Like other…
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…
MyCn18: An Hourglass Nebula
The sands of time are running out for the central star of this hourglass-shaped planetary nebula . With its nuclear fuel exhausted, this brief, spectacular, closing phase of a…
55 Cancri: Familiar Planet Discovered
Is our Solar System unique? The discovery of a Jupiter -like planet in a Jupiter-like orbit around nearby Sun -like star 55 Cancri , announced yesterday, gives a new indication…
The Tarantula Zone
The Tarantula Nebula is more than 1,000 light-years across - a giant emission nebula within our neighboring galaxy the Large Magellanic Cloud . Inside this cosmic arachnid lies a…
A Partial Eclipse Over the Golden Gate Bridge
Part of the Sun disappeared behind the Moon earlier this week. Previously, the waning Moon was best visible from all places on Earth during the early morning hours because it led…
Inside the Eagle Nebula
From afar, the whole thing looks like an Eagle . A closer look of the Eagle Nebula , however, shows the bright region is actually a window into the center of a larger dark shell…
Annular Eclipse: The Ring of Fire
Today, a few lucky people will see a “ring of fire.” That's a name for the central view of an annular eclipse of the Sun by the Moon . At the peak of this eclipse , the middle of…
A Chamaeleon Sky
A photogenic group of nebulae can be found toward Chamaeleon , a constellation visible predominantly in skies south of the Earth's equator . Celestial objects visible there…
A Fleeting Eclipse
A lunar eclipse can be viewed in a leisurely fashion. Visible to anyone on the night side of planet Earth (weather permitting), totality often lasts an hour or so as the moon…
Portrait of an Infant Solar System
This infant solar system was discovered posing along the lonely outskirts of the Rho Ophiuchi dark cloud , a star forming region 500 light-years from Earth. Enlarged in an…
Cone Nebula Infrared Close-Up
After astronauts repaired NICMOS - the Near Infrared Camera and Multi-Object Spectrometer - during the latest Hubble Space Telescope servicing mission , astronomers were quick to…
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…
A Martian Metamorphosis
Is it an Escher, or Mars? Three different types of surfaces visible in the North Polar Cap of Mars morph into each other in a way perhaps reminiscent of the works of M. C. Escher…
Galaxy NGC 4388 Expels Huge Gas Cloud
Why are huge clouds of gas billowing from spiral galaxy NGC 4388? The extent of the gas clouds, over 100,000 light-years , was unexpected before the Subaru Telescope took the…
Cracks and Ridges on Europa
Which way to the interstate ? What appears to be a caricature of a complex highway system on Earth is actually a system of ridges and cracks on the icy surface of Jupiter's moon…
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…
In Chandor Chasma on Mars
Scroll right and dive into a spectacular canyon on Mars . This daytime infrared view , recently recorded by the THEMIS camera on board the orbiting Mars Odyssey spacecraft, covers…
Orion Nebulosities
Adrift 1,500 light-years away in one of the night sky's most recognizable constellations , the glowing Orion Nebula and the dark Horsehead Nebula are contrasting cosmic vistas.…
Viewing discoveries from 22 June 2002 through 30 May 2002.