Astronomy Picture Of the Day (APOD)The Great Basin on Tethys
Some moons wouldn't survive the collision. Tethys, one of Saturn's larger moons at about 1000 kilometers in diameter, survived the collision, but sports today the expansive impact crater Odysseus. Sometimes called...
UB313: Larger than Pluto
What do you call an outer Solar System object that is larger than Pluto? Nobody is yet sure. The question arose recently when 2003 UB313, an object currently twice as far out as Pluto and not in the plane with the rest of the planets, was verified recently to be 30 percent wider than Pluto.
The N44 Superbubble
What created this gigantic hole? The vast emission nebula N44 in our neighboring galaxy the Large Magellanic Cloud has a large, 250 light-year hole and astronomers are trying to figure out why. One possibility is particle winds expelled by massive stars in the bubble's interior that are pushing out the glowing gas.
A Sun Pillar in Red and Violet
Sometimes the unknown is beautiful. In 2000 February near Lake Tahoe, Nevada, two amateur photographers noticed an unusual red column of light rise mysteriously from a setting sun. During the next few minutes, they were able to capture the pillar and a photogenic sunset on film.
A nearly full Moon and planet Earth's shadow set together in this scene captured on January 13th from snowy Mt. Jelm, home of the Wyoming Infrared Observatory. For early morning risers (and late...
Cosmic Tornado HH 49 50
Light-years in length, this cosmic tornado is actually a powerful jet cataloged as HH (Herbig-Haro) 49/50 blasting down from the top of a Spitzer Space Telescope view. Though such energetic outflows are well known...
Thor s Helmet in H Alpha
Near picture center, the helmet-shaped structure with wing-like appendages is popularly called Thor's Helmet. Cataloged as NGC 2359, the striking nebula is located about 15,000 light-years away in the constellation Canis Major.
Venus Just After Sunset
Is that Venus or an airplane? A common ponderable for sky enthusiasts is deciding if that bright spot near the horizon is the planet Venus. Usually, an airplane will show itself by moving significantly in a few moments. Venus will set only slowly as the Earth turns.
Huygens on Titan Illustrated
If you could stand on Titan, what might you see? About one year ago the robotic Huygens probe landed on the enigmatic moon of Saturn and sent back the first ever images from beneath Titan's thick cloud layers.
NGC 1999: South of Orion
South of the large star-forming region known as the Orion Nebula, lies bright blue reflection nebula NGC 1999. The nebula is marked with a dark inverted T-shape at the lower left in a broad cosmic vista that spans over 10 light-years.