11 February 2014, 05:00 PM ET
The Gemini program tested docking, rendezvous, spacewalks and long-duration spaceflight in preparation for the moon missions of the late 1960s.
10 February 2014, 06:50 PM ET
Mercury was a NASA program to prove that astronauts could function effectively in space for minutes to hours at a time.
04 February 2014, 03:11 PM ET
NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE) launched in September 2013. Here is everything you need to know about it.
31 January 2014, 11:48 PM ET
Gordon Cooper had the longest flight among the original Mercury astronauts.
31 January 2014, 12:46 AM ET
Scott Carpenter, one of the original Mercury astronauts, explored space and later the sea.
30 January 2014, 12:49 AM ET
Deke Slayton was selected for the Mercury program, but had to wait more than a decade to fly in space after concerns about an erratic heartbeat pulled him out of the flight rotation.
29 January 2014, 01:45 AM ET
Wally Schirra, one of the original Mercury Seven astronauts, was the only one who flew in the Mercury, Gemini and Apollo programs.
28 January 2014, 01:46 AM ET
Gus Grissom, one of the original Mercury Seven, also flew on a Gemini mission. He died during training for the first Apollo mission.
27 January 2014, 10:44 PM ET
When stars can't handle their nuclear fuel, they explode in a brilliant burst of light.
22 January 2014, 01:00 PM ET
Ceres is a dwarf planet, the only one located in the inner reaches of the solar system. It is the largest object in the asteroid belt.
15 January 2014, 10:29 PM ET
The density of the universe determines its shape. It could be spherical, saddle-shaped or flat.
06 January 2014, 01:22 PM ET
Kepler-69c, also known as KOI 172.02, is a planet candidate discovered by the Kepler space telescope. It is a "super-Earth" that could hold water on its surface.
02 January 2014, 06:53 PM ET
The rocky planet Kepler-62f could be covered in water, as long as there is enough cloud around the planet to warm the surface below.
31 December 2013, 07:13 PM ET
Kepler-62e is an alien planet that is believed to be in the habitable zone of its red dwarf parent star.
31 December 2013, 06:53 PM ET
Kepler-22b is an alien planet that's a bit larger than Earth, but it's in the habitable region of its star.
30 December 2013, 06:04 PM ET
A do-it-yourself Galilean telescope makes an excellent and inexpensive starter telescope — or science fair project.
24 December 2013, 12:36 AM ET
Based on what we can observe, the universe appears to be almost 28 billion light-years in diameter. However, it is far larger than that.
20 December 2013, 06:21 PM ET
The universe is approximately 13.8 billion years old.
03 December 2013, 06:22 PM ET
Gliese 581g is an extra-solar planet that was discovered in 2010, but quickly cast into doubt by other studies. The original discoverers then published a follow-up paper in 2012 defending their find.
02 December 2013, 01:53 PM ET
A black dwarf is all that is left after a white dwarf star burns off all of its heat, but retains its mass.
02 December 2013, 01:49 PM ET
Brown dwarfs never burn fusion at their core, so scientists sometimes refer to them as "failed stars."
27 November 2013, 11:18 PM ET
Most of the star nearest to Earth are red dwarfs, but they are too dim to be seen with the naked eye.
26 November 2013, 06:11 PM ET
Most stars in the universe will eventually burn off all of their hydrogen and become dead husks called white dwarfs.
25 November 2013, 04:46 PM ET
Shaula, the 24th-brightest star, is a possible multiple-star system in the constellation Scorpius.
22 November 2013, 06:36 PM ET
Gacrux is a variable star that blows strong winds through its system.
21 November 2013, 12:24 AM ET
Beta Crucis is a possible multiple star system in the Southern Cross.
15 November 2013, 05:24 PM ET
NASA's newest Mars probe is expected to study the atmosphere of the Red Planet in amazing new detail.
13 November 2013, 05:10 PM ET
A simple planetarium can be built out of corrugated cardboard.
12 November 2013, 11:55 PM ET
Achernar, the ninth-brightest star, is a binary system, with one of the stars rotating extremely quickly.
11 November 2013, 09:58 PM ET
Rigel Kentaurus (better known as Alpha Centauri) is in the closest star system to Earth and is one of the brightest stars in our sky.
30 October 2013, 01:36 AM ET
The Quadrantids are a meteor shower in January that peak for only about six hours, are named for a constellation that no longer exists and come from an asteroid rather than a comet.
23 October 2013, 06:47 PM ET
The Lyrid meteor shower has been observed for more than 2,700 years.