27 March 2013, 07:00 PM ET
The two small bodies that orbit the red planet raise a number of questions about the formation of the early solar system.
26 March 2013, 03:11 PM ET
Ed Mitchell's experience aboard Apollo 14 launched his exploration of the nature of human consciousness.
26 March 2013, 03:02 PM ET
Stuart Roosa's skills were put to the test when a docking mechanism didn't work.
21 March 2013, 06:52 PM ET
The moon's orbit brings it 6 feet closer to the red planet every century.
21 March 2013, 06:48 PM ET
Deimos' radius is only 3.9 miles. The tiny moon zips around Mars in only 30 hours and is so close to its parent planet that it was missed for centuries.
20 March 2013, 03:27 PM ET
Jim Lovell was for years NASA's most-traveled astronaut. He flew on four missions, including Apollo 13, whose crew had to survive in space after a crippling explosion.
20 March 2013, 03:22 PM ET
Jack Swigert survived the perilous Apollo 13 mission, then took a different kind of risk: entering politics.
20 March 2013, 03:03 PM ET
Astronaut Fred Haise was assigned to two Apollo missions where he would have walked on the moon, but he never made it there.
12 March 2013, 01:30 PM ET
Missions to Mars have searched, but haven't found definite proof of life past or present.
08 March 2013, 05:00 PM ET
Millions of pieces of space junk swarm around the Earth.
08 March 2013, 04:57 PM ET
Olympus Mons rises 16 miles above the Martian surface, making it the solar system's tallest volcano.
07 March 2013, 06:00 PM ET
Wernher von Braun led the development of the rockets that carried the first Americans into space and onto the moon.
06 March 2013, 05:18 PM ET
Comet Elenin was a minor comet that caused major doomsday rumors on Earth, even after it broke up after a solar storm.
04 March 2013, 07:03 PM ET
Hermann Oberth's ideas about missiles and space travel make him one of three "fathers of rocketry."
01 March 2013, 03:25 PM ET
Comet Hartley 2, discovered in 1986, has an odd shape, spins on two axes and spews out a jets of water and carbon dioxide.
28 February 2013, 06:35 PM ET
Comet Hyakutake's long tail astounded skywatchers when it approached Earth in 1996.
27 February 2013, 06:19 PM ET
Tsiolkovsky developed insights into space travel and rocket science that are still in use over a hundred years later.
25 February 2013, 12:41 PM ET
Goddard, the American father of modern rocketry, built and tested the world's first liquid-fuel rocket.
22 February 2013, 06:43 PM ET
Comet Hale-Bopp put on a spectacular show when it swung around the sun in the late 1990s.
22 February 2013, 11:24 AM ET
The Milky Way is a barred spiral galaxy, about 100,000 light-years across. We live on one of its minor spurs, the Orion Arm.
20 February 2013, 02:17 PM ET
The comet's frequent recurrence has played a part in historical events for millennia.
19 February 2013, 02:35 PM ET
When comet Shoemaker-Levy 9 smashed into Jupiter in 1994, it sent ripple effects both physically and politically.
19 February 2013, 10:50 AM ET
In the 1500s, when most believed Earth was the center of the universe, Nicolas Copernicus proposed his theory that the planets revolved around the sun.
15 February 2013, 03:05 PM ET
Kansas farm boy Clyde Tombaugh looked to the stars and found a new planet.
14 February 2013, 04:24 PM ET
The Navstar constellation of satellites provides the signals for a global positioning system.
13 February 2013, 04:56 PM ET
Percival Lowell's study of Mars, while flawed, fueled public enthusiasm for the Red Planet.
12 February 2013, 05:47 PM ET
The twin Telstar satellites not only ushered in a new era of satellite communication, but also inspired a hit song.
11 February 2013, 10:31 AM ET
Landsat is a series of satellites that observe conditions on Earth.
08 February 2013, 05:47 PM ET
Black holes are some of the strangest and most mysterious objects in the universe.
05 February 2013, 04:33 PM ET
The Soviet Union's Mir space station – later operated by Russia – served as an important test bed for how missions should be run over several months.
04 February 2013, 02:37 PM ET
Tycho Brahe made many significant contributions to astronomy.
01 February 2013, 06:40 PM ET
Skylab represented the United States' first effort at long human space missions.