Astronomy Picture Of the Day (APOD)M31: The Andromeda Galaxy
Andromeda is the nearest major galaxy to our own Milky Way Galaxy. Our Galaxy is thought to look much like Andromeda. Together these two galaxies dominate the Local Group of galaxies. The diffuse light from Andromeda is caused by the hundreds of billions of stars that compose it.
M20: The Trifid Nebula
The vivid blue and violet colors present in the Trifid Nebula result from the abundance of young stars there. The light from young massive stars is quite blue and has the ability to remove electrons from surrounding gas. When these electrons re-combine with the gas, radiation rich in blue and violet light is emitted.
The Face on Mars
This image, showing what looks to be a human face sculpted on the martian surface, was produced using data from NASA's Viking 1 orbiter in 1976. Described in a press release...
The Search for Life on Mars
Although images of Mars taken from space revealed the planet to have a barren and cratered surface, scientists did not give up the search for martian life. In 1976 NASA's Viking project succeeded in landing two robot probes on the surface of Mars.
The Grand Canyon of Mars
The Mariner Valley, also known as the Valles Marineris canyon system, appears in this mosaic of images from NASA's Viking spacecraft as a huge gouge across the red planet. This "Grand Canyon" of Mars is about 2500 miles long and up to 4 miles deep.
The Mountains of Mars
Volcanic activity on Mars has produced towering mountains. The largest one, Olympus Mons, is pictured here in this Viking Orbiter image. Olympus Mons is a shield volcano nearly 15 miles high and over 300 miles wide at its base.
Cygnus Loop Supernova Shockwave
15,000 years ago a star in the constellation of Cygnus exploded. This picture shows a portion of a shockwave from this supernova explosion still expanding past nearby stars. The collision of this gaseous...
"Yes, I have been to Barsoom again ..." begins John Carter in Edgar Rice Burroughs' 1913 science fiction classic "The Gods of Mars". In Burroughs' novels describing Carter's adventures on Mars, "Barsoom" is the local name for the red planet.
The Exploration of Mars
Thirty years ago NASA's exploration of Mars began. In July of 1965 the Mariner 4 spacecraft flew within 6,000 miles of Mars and returned 21 pictures of the mysterious red planet. NASA...
The Crater Chain
NASA's robot spaceprobe Voyager 1, took this closeup image of the surface of Jupiter's crater scarred moon Callisto in 1979. A mysterious chain of craters is seen to extend diagonally across the image (upper left to lower right). What could cause the craters to line up in such a regular fashion?