An extrasolar planet, or exoplanet, is a planet beyond the Solar System. As of 11 November 2006, 209 extrasolar planets have been discovered.
Known exoplanets are members of planetary systems that ... > more
Precession refers to a change in the direction of the axis of a rotating object. In certain contexts, "precession" may refer to the precession that the Earth experiences, the effects of this type of ... > more
A meteor is the visible path of a meteoroid that enters the Earth's (or another body's) atmosphere, commonly called a shooting star or falling star. A meteor is a meteoroid that has entered the ... > more
Colonel Buzz Aldrin, Sc.D (born January 20, 1930 as Edwin Eugene Aldrin, Jr.) is an American pilot and astronaut who became the second human to set foot on the Moon (after Neil Armstrong) during the ... > more
An ion thruster (or ion drive), one of several types of spacecraft propulsion, uses beams of ions - electrically charged atoms or molecules - for propulsion. The precise method for accelerating the ... > more
A meteorite is a small extraterrestrial body that impacts the Earth's surface. While in space they are called meteoroids, and while falling through Earth's atmosphere they are called meteors. These ... > more
Spitzer Space Telescope (formerly the Space Infrared Telescope Facility [SIRTF]) is an infrared space observatory, the fourth and final of NASA's Great Observatories. The first images taken by SST ... > more