The Kepler spacecraft searches for planets in the habitable zone, which is the region around a star where the temperature permits water to be liquid on the surface of a planet. Liquid water is considered essential for the existence of life.
Kepler will hunt for planets using a specialized one-meter diameter telescope (3.3 feet) called a photometer. The photometer will continuously measure the precise brightness of more than 100,000 stars, waiting for the stars to “wink” when orbiting planets pass in front of them.
These events, called “transits” occur each time a planet crosses the line-of-sight between the planets parent star and the Kepler telescope. When this happens, the planet blocks some of the light from the star, resulting in the periodic dimming. This periodic signature is used to detect the planet and to determine its size and orbit.
By monitoring a large number of stars, Kepler will permit astronomers to estimate the total number of Earth-size planets orbiting in the habitable zone around stars in our galaxy. If Kepler does not discover any such planets, scientists will be able to conclude that we are likely alone in the galaxy.
Additional Quick Facts
Delta II Fuel: Nine strap-on solid rocket motors. The first stage uses kerosene and liquid oxygen. The second stage uses hydrazine and nitrogen tetroxide.
Orbital Period: 371 days
Spacecraft Dimensions: 2.7 meters (9ft) diameter, 4.7 meters (15.3 ft) high
Weight: 1052.4 kg (2,320.1 lbs) at launch
Weight Breakdown:
- Spacecraft- 562.7 kg (1240.5 lbs)
- Photometer- 478 kg (1043.9 lbs)
- Hydrazine Propellant- 11.7 kg (25.8 lbs)
Photometer: The sole Kepler instrument is a photometer—a Schmidt-type telescope consisting of a .95-meter (37-inch) aperture and a 1.4-meter (55-inch) primary mirror. This configuration allows for a 105 square degree field of view. Kepler’s photometer has a field of view 33,000 times greater than the Hubble Space Telescope. The photometer features a focal plane array with more than 95 million pixels. The focal plane array is the largest camera NASA has ever flown in space.
Downloads
Links
- For more information please visit: www.kepler.nasa.gov
- To receive Twitter updates, please visit: twitter.com/nasakepler
- NASA’s Kepler multimedia site
- “One year ago, Boulder-built Kepler was launched to look for Earth-like planets” by Laura Snider
- “Kepler Spacecraft to Hunt Earth-like Worlds” by Leonard David (also on MSNBC)
- CU-Boulder Students to be at Controls for NASA’s March Planet-Hunting Mission
Media Contacts
- Stephanie Renfrow
Laboratory for Atmospheric and Space Physics
303-735-5814 - Bill Possel
Laboratory for Atmospheric and Space Physics
303-492-6867 - Jim Scott
University of Colorado
(303) 492-3114 - Roz Brown
Ball Aerospace & Technologies Corp.
Boulder, Colo.
Spacecraft
(303) 533-6059
