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.
Saturn at the Lunar Limb
Gliding through the sky on Wednesday evening, February 20th, a first quarter Moon seemed to run over bright planet Saturn as viewed from much of North America. In this sharp…
Comet Ikeya-Zhang
Comet Ikeya-Zhang is presently heading north in planet Earth's sky , framed by stars of the constellation Cetus. The comet was discovered as a faint, telescopic object near the…
Oddities of Star Cluster NGC 6397
One of these stars is blinking. This star , a member of globular cluster NGC 6397, is noteworthy not just because it blinks, but because it blinks so fast and because its…
Water-Ice Imaged in Martian Polar Cap
Does water exist today on Mars? Yes, although the only place on Mars known to have water is the North Polar Cap , and that water is frozen. Views of this potentially life-enabling…
A Radio Vista of Cygnus
Shells of ancient supernovas , cocoons surrounding newborn stars , and specks from distant quasars highlight this tremendous vista toward the constellation of Cygnus . The…
The Local Bubble and the Galactic Neighborhood
What surrounds the Sun in this neck of the Milky Way Galaxy ? Our current best guess is depicted in the above map of the surrounding 1500 light year s constructed from various…
Miranda, Chevron, and Alonso
Miranda is a bizarre world which surely had a tempest uous past. The innermost of the larger Uranian moons, Miranda is almost 300 miles in diameter and was discovered on today's…
Saturn: Lord of the Rings
Born on today's date in 1564, Galileo used a telescope to explore the Solar System. In 1610, he became the first to be amazed by Saturn's rings. After nearly 400 years, Saturn's…
Solar System Portrait
On another Valentine's Day (February 14, 1990), cruising four billion miles from the Sun, the Voyager 1 spacecraft looked back to make this first ever family portrait of our Solar…
The Great Nebula in Orion
Few astronomical sights excite the imagination like the nearby stellar nursery known as the Orion Nebula . The Nebula's glowing gas surrounds hot young stars at the edge of an…
Methane Earth
Can you help in reducing this blanket of methane gas that is warming up our Earth ? Recent evidence holds that methane (CH 4 ) is second only to carbon dioxide (CO 2 ) in creating…
Reflection Nebula M78
An eerie blue glow and ominous columns of dark dust highlight M78 , one of the brightest reflection nebula on the sky. M78 is visible with a small telescope toward the…
The Local Interstellar Cloud
The stars are not alone. In the disk of our Milky Way Galaxy about 10 percent of visible matter is in the form of gas, called the interstellar medium (ISM). The ISM is not…
Moon Over Mongolia
Fighting clouds and the glow of city lights, a young Moon shines over the western horizon of Mongolia's capital, Ulaan-Baatar . The thin sunlit crescent is about 2 days old and…
PKS 1127-145: Quasar View
The quasar known as PKS 1127-145 lies ten billion light- years from our fair planet. A Hubble Space Telescope view in the left panel shows this quasar along with other galaxies as…
Coronal Hole
This ominous, dark shape sprawling across the face of the active Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field opens…
The Cosmic Infrared Background
What cosmic wallpaper is on the sky? The answer depends on the type of light considered, and for some wavelengths , all the cluttering material in the foreground makes it still…
Giant Storm Systems Battle on Jupiter
Two of the largest storm systems on Jupiter are colliding, and nobody is sure what will result. The larger storm is the famous Great Red Spot , while the smaller is a large white…
Comet LINEAR (WM1) Shines in the South
A new comet has brightened unexpectedly and is currently visible to unaided observers of southern skies. Comet C/2000 WM1 (LINEAR) is now reported by some observers to be at third…
The Coma Cluster of Galaxies
Almost every object in the above photograph is a galaxy. The Coma Cluster of Galaxies pictured above is one of the densest clusters known - it contains thousands of galaxies .…
Centaurus A: The Galaxy Deep Inside
Deep inside Centaurus A , the closest active galaxy to Earth, lies ... another galaxy! Cen A is a giant elliptical galaxy a mere 10 million light-years distant with a central…
Balloon TIGER
Where does a two-ton tiger hang out? Well, in this case the Trans-Iron Galactic Element Recorder ( TIGER ) experiment hangs from a mobile crane on the far left in this panorama…
EUVE Sky Map
The stars beyond the Sun and the distant galaxies should be undetectable at extreme ultraviolet wavelengths . At least that was the conventional wisdom when it was first realized…
Moonrise Over Seattle
Is the Moon larger when near the horizon? No -- as shown above, the Moon appears to be very nearly the same size no matter its location on the sky. Oddly, the cause or causes for…
Viewing discoveries from 22 February 2002 through 30 January 2002.