Astronomy Picture Of the Day (APOD)Earth at Twilight
No sudden, sharp boundary marks the passage of day into night in this gorgeous view of ocean and clouds over our fair planet Earth. Instead, the shadow line or terminator is diffuse and shows the gradual transition to darkness we experience as twilight.
Titan s Cryovolcano
Investigators suspect the domed feature detailed above is an ice volcano, or cryovolcano, seen in infrared light through the hazy atmosphere on Saturn's moon Titan. Since Titan's surface temperature is around -180...
Venus Returns to the Evening Sky
This serene image of boats moored in the harbor of l'нle-Tudy, Bretagne, France was taken on June 1st, about an hour after sunset. It also features Venus, third brightest celestial object after the Sun and Moon.
Rampaging Supernova Remnant N63A
What has this supernova left behind? As little as 2,000 years ago, light from a massive stellar explosion in the Large Magellanic Clouds (LMC) first reached planet Earth. The LMC is a close...
Galaxies in View
Galaxies abound in this cosmic scene, a well chosen telescopic view toward the northern constellation of Ursa Major. Most noticeable are the striking pair of spiral galaxies - NGC 3718 (above, right) and NGC 3729 (below center) - a mere 52 million light-years distant.
Saturn: Dirty Rings and a Clean Moon
Eating surface ice from Enceladus might be healthier than eating ice from Saturn's rings -- it certainly appears cleaner. From their apparent densities and reflectance properties, both the rings of Saturn and its shiniest moon, Enceladus, are thought to be composed predominantly of water ice.
A Milky Way Band
Most bright stars in our Milky Way Galaxy reside in a disk. Since our Sun also resides in this disk, these stars appear to us as a diffuse band that circles the sky.
First US Spacewalk
In 1965, forty years ago on June 3rd, astronaut Edward White made the first U.S. spacewalk. Tethered to his Gemini IV capsule, White is pictured above holding a compressed gas "zip gun" for maneuvers in his right hand.
M27: The Dumbbell Nebula
The first hint of what will become of our Sun was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of diffuse objects not to be confused with comets.
Sculpting the South Pillar
Eta Carinae, one of the most massive and unstable stars in the Milky Way Galaxy, has a profound affect on its environment. Found in the the South Pillar region of the Carina Nebula, these...