26 October 2012, 12:10 PM ET
The Viking mission to Mars gave scientists their first look at the Martian landscape.
24 October 2012, 03:17 PM ET
Mars Express is the European Space Agency's first spacecraft to fly to another planet.
23 October 2012, 02:40 PM ET
The space shuttle Discovery flew 39 times into space, more than any spacecraft.
22 October 2012, 07:25 PM ET
The surface of the moon experiences great extremes in temperature, from boiling hot to freezing cold.
19 October 2012, 02:03 PM ET
The moon is about one-fourth as big as Earth, relatively large for a planet's satellite.
18 October 2012, 03:32 PM ET
Endeavour was the final addition to NASA's space shuttle fleet.
16 October 2012, 04:35 PM ET
Three stars in this system are the sun's nearest stellar neighbors.
16 October 2012, 01:21 PM ET
The space shuttle Challenger was one of NASA's greatest triumphs and also its darkest tragedy.
15 October 2012, 01:02 PM ET
The moon's atmosphere is a very thin layer of widely dispersed gases.
09 October 2012, 05:58 PM ET
Without going into space, the first space shuttle prepared astronauts for future missions.
08 October 2012, 02:02 PM ET
An overview of NASA HQ, which oversees the space agency's many science, exploration and spaceflight activities.
29 September 2012, 01:30 PM ET
Falcon 9 lifts SpaceX's Dragon spacecraft to the ISS.
28 September 2012, 04:59 PM ET
Explorer 1 launched the United States into the Space Race.
28 September 2012, 12:29 PM ET
The average temperature is 61 F (16 C), but temperatures vary greatly around the world.
28 September 2012, 02:37 AM ET
A timeline of notable spaceflight events across five decades of exploration.
26 September 2012, 06:14 PM ET
Pioneer 11 revealed the gas giants in unprecedented detail.
26 September 2012, 02:23 PM ET
Earth has multiple layers, consisting of the core, mantle and crust.
25 September 2012, 06:55 PM ET
What was the first animal in space? The answer may have you buzzing.
25 September 2012, 01:35 PM ET
The mission is still sending back data and fueling new discoveries.
24 September 2012, 06:47 PM ET
The Mars Pathfinder mission included the first successful rover on
21 September 2012, 01:04 PM ET
When the sun shucks off its outer layers, it will leave a beautiful cloud of gas.
20 September 2012, 06:44 PM ET
A brief look at "America's spaceport," which is in a period of transition after the space shuttle's 2011 retirement.
20 September 2012, 01:40 PM ET
Voyager 2 is the only spacecraft to have visited all four giant outer planets in the solar system.
19 September 2012, 06:52 PM ET
Earth is the only planet in the solar system with an atmosphere that can sustain life.
18 September 2012, 11:10 PM ET
America's space shuttles were NASA's orbital workhorses.
18 September 2012, 06:52 PM ET
Albert Einstein determined that massive objects cause a distortion in space-time, which is felt as gravity.
18 September 2012, 02:08 PM ET
Pioneer 10 was NASA's first mission to the outer planets.
17 September 2012, 04:14 PM ET
Earth is the fifth largest planet in the solar system and the densest.
17 September 2012, 12:12 PM ET
The answer is one 1 astronomical unit. How far is that?
14 September 2012, 03:47 PM ET
The Apollo 9 crew had to contend with human illness as they flew the lunar module in space for the first time.
13 September 2012, 06:10 PM ET
Searching for a "theory of everything," physicists are considering tiny bits of vibrating string.
13 September 2012, 04:52 PM ET
The lunar module Snoopy got within 50,000 feet of the moon's surface.