Are there other planets, orbiting other stars, with characteristics similar to Earth? The Kepler
Mission is designed to find Earth-size planets in orbit around stars like our Sun outside of the
solar system.
MISSION GOALS
Launched on March 6, 2009, the scientific goal of the Kepler Mission is to explore the structure and diversity of planetary systems, with a special emphasis on the detection of Earth-size planets. It will survey the extended solar neighborhood to detect and characterize hundreds of terrestrial and larger planets in or near the "habitable zone," defined by scientists as the distance from a star where liquid water can exist on a planet's surface. The results will yield a broad understanding of planetary formation, the frequency of formation, the structure of individual planetary systems, and the generic characteristics of stars with terrestrial planets.
A NEW APPROACH
Kepler satellite
Kepler's photometer (a device that measures the brightness of light) will function like a giant camcorder with a 95 cm (37 inch) diameter lens, flying through space. It will continuously measure the brightness of 100,000 stars and send back information to be analyzed by the science team. When a planet moves in front of a star, as viewed by an observer, the star will get dimmer for several hours, indicating that a planet has passed by. This "transit" of planets across the faces of stars will be recorded by sensors on the photometer and will provide the raw data, which will lead to the determination of the planet's size and the orbital period.
About 80 gas giant planets have been discovered outside of our solar system to date, but this past approach cannot detect planets much smaller than Jupiter.
Only in the last few years have the technologies necessary to conduct a search for small rocky, or
terrestrial, planets with high precision reached maturity. The Kepler Mission will be the first search capable of detecting Earth-size planets.
SIGNIFICANCE OF THE MISSION
Kepler will monitor 100,000 stars similar to our sun for four years. The results will be extremely important either way. If Kepler detects many habitable, Earth-size planets, it could mean the universe is full of life. Kepler would then be a stepping stone to the next extensive search for habitable planets and life, the Terrestrial Planet Finder. If nothing is found, it may mean we're alone in the galaxy.
MISSION MANAGEMENT
The Kepler mission is managed for NASA by the Jet Propulsion Laboratory, Pasadena, CA. The Principal Investigator is William Borucki of NASA Ames Research Center. Ball Aerospace and Technologies Corp., Boulder, CO, is building the spacecraft.
For more complete information about the Kepler Mission, click here.
