27 September 2012, 02:33 PM ET
NASA's Messenger mission has spent several years mapping Mercury, which was poorly understood for decades.
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.
12 September 2012, 01:43 PM ET
The launch of the world's first satellite was the birth of the Space Age.
10 September 2012, 02:17 PM ET
The first crewed launch of the program proved that the Apollo spacecraft could get astronauts to the moon.
07 September 2012, 05:51 PM ET
One of the astronauts on Apollo 16 left his family on the moon.
06 September 2012, 02:11 PM ET
Astronauts on the moon take the lunar rover for a spin.
05 September 2012, 05:24 PM ET
Alan Shepard's return to space was marked by a tough climb and a tee shot.
04 September 2012, 03:59 PM ET
Caroline Herschel was the first woman to discover a comet. She made several contributions to the field of astronomy
04 September 2012, 01:51 PM ET
Astronomer William Herschel discovered the planet Uranus and 2,500 celestial objects.
31 August 2012, 10:47 AM ET
The Apollo 12 crew needed to land close to their target area to fulfill their mission.
30 August 2012, 02:17 PM ET
The astronaut was also the fifth man to walk on the moon.
29 August 2012, 01:31 PM ET
The Apollo 8 mission took astronauts around the moon for the first time.
28 August 2012, 03:46 PM ET
The three astronauts on board — Gus Grissom, Ed White, and Roger Chaffee — died. The tragedy changed the way NASA operates.
24 August 2012, 04:15 PM ET
The final Apollo mission took the first scientist to the moon.
23 August 2012, 06:58 PM ET
The first American to orbit Earth made history twice.
23 August 2012, 06:13 PM ET
These powerful objects offer a glimpse into the origins of the universe.
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