Astronomy Picture Of the Day (APOD)The Voyagers' Message in a Bottle
Launched twenty-five years ago, NASA's Voyager 1 and 2 spacecraft are now over 10 billion kilometers from the Sun. Still operational, the Voyagers are being tracked and commanded through the Deep Space Network.
Simeis 147: Supernova Remnant
It's easy to get lost following the intricate filaments in this stunningly detailed image of faint supernova remnant Simeis 147. Seen towards the constellation Taurus it covers nearly 3 degrees (6 full moons)...
The Pelican in the Swan
The Pelican Nebula, also known as IC 5070, lies about 2,000 light-years away in the high and far-off constellation of Cygnus, the Swan. This picture spans a portion of the magnificent nebula about 30 light-years wide.
3D Mars: Northern Terra Meridiani
In this spectacular 3D stereoscopic view from orbit, steep-sided, flat-topped hills stand above the Terra Meridiani region of Mars. Seen best with red/blue glasses (red for the left eye), the structures are reminiscent of buttes and mesas found in southwestern areas of the North American continent on planet Earth.
Valles Marineris: The Grand Canyon of Mars
The largest canyon in the Solar System cuts a wide swath across the face of Mars. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep.
The Mysterious Voynich Manuscript
The ancient text has no known title, no known author, and is written in no known language: what does it say and why does it have many astronomy illustrations? The mysterious book was once bought by an emperor, forgotten on a library shelf, sold for thousands of dollars, and later donated to Yale.
Nebula Nova Cygni Turns On
Old photographs show no evidence of the above nebula. In 1992, a white dwarf star toward the constellation of Cygnus blew off its outer layers in a classical nova explosion: an event called Nova Cygni 1992.
Cas A Supernova Remnant in X Rays
The complex shell of a star seen to explode 300 years ago is helping astronomers to understand how that star exploded. This Chandra Observatory image of supernova remnant Cassiopeia A (Cas A) shows unprecedented detail in three x-ray colors.
Island Universe, Cosmic Sand
On August 13, while counting Perseid meteors under dark, early morning Arizona skies, Rick Scott set out to photograph their fleeting but fiery trails. The equipment he used included a telephoto lens and fast color film. After 21 pictures he'd caught only two meteors, but luckily this was one of them.
Shell Game in NGC 300
Featured in color in yesterday's episode, big, beautiful, face-on spiral galaxy NGC 300 is seen here through a narrow filter that transmits only the red light of hydrogen atoms. Ionized by energetic starlight, a hydrogen atom emits the characteristic red H-alpha light as its single electron is recaptured and transitions to lower energy states.