Kepler Mission

Kepler Mission

Kepler Mission will use a unique spaceborne photometer specifically designed to search for Earth-sized planets around stars beyond our solar system. “The KeplerMission will, for the first time, enable humans to search our galaxy for Earth-size or even smaller planets,” said principal investigator William Borucki of the Planetary Systems Branch of the Space Science Division. “With this cutting-edge capability, Kepler may help us answer one of the most enduring questions humans have asked throughout history: are there others like us in the universe?” The Kepler Mission is specifically designed to survey the extended solar neighborhood to detect and characterize hundreds of terrestrial and larger planets in or near the habitable zone and provide fundamental progress and large leaps in our understanding of planetary systems. The results will yield a broad under-standing of planetary formation, the frequency of formation, the structure of individual planetary systems and the generic characteristics of stars with terrestrial planets.

Kepler measures repetitive stellar brightness changes on the order of 100 parts per million last-ing for 2 to 16 hours caused by transiting terrestrial planets. The planet’s orbit is calculated from the period of the transits. The size of the planet is calculated from the transit depth. The proposed differential photometer continuously and simultaneously monitors the brightness of 100,000 dwarf stars for four years; long enough to see four transits of a terrestrial planet in the habitable zone of a solar-like star. To obtain the required precision, the photometer must be spaceborne; this also eliminates the day-night and seasonal cycle interruptions of ground-based observing. The results likely consist of a mix of all of the above. From these results, NASA can explore Photometer / Spacecraft the structure and diversity of planetary systems. The results are also still significant even if no planets are found, since the mission is designed to detect so many terrestrial planets.

Last Spring, the Kepler space telescope was launched on a three and a half to six year mission to find Earth sized and smaller planets orbiting other suns within the habitable range. During that time, the Kepler mission is planned to scan a hundred thousand main sequence stars in hope of finding such planets that may contain life. The Kepler mission will attempt to find planets orbiting other stars by using the “transit method” of exo-planet detection. This is done by calculating the decrease in the amount of brightness in a star when a planet moves across it. If the decrease occurs at least twice in a periodic fashion, the discovery of a planet is assumed. The decrease in the amount of brightness and the size of the star determines the size of the planet. The size of the orbit is determined by the time it takes the planet to orbit the star and the star’s mass. The size of the orbit and the temperature of the star are used to determine what the temperature of the planet is. Thus the planet can be classified as uninhabitable or possibly habitable.