The scientific objective of the Kepler Mission is to explore the
structure and diversity of extrasolar planetary systems. More
specifically, this is achieved by observing a large sample of
stars to: Goal 1: Determine the frequency of terrestrial and
larger planets in or near the habitable zone of a wide variety
of spectral types of stars. The frequency of planets is derived
from the number and size of planets found and from the number
and spectral type of stars monitored. Even a null result would
be highly meaningful because of the large number of stars
searched and the low false alarm rate. Goal 2: Determine the
distributions of sizes and orbital semi-major axes of these
planets. The planet's area is found from the fractional
brightness decrease and the stellar area. For a detection with a
statistical significance of >8 sigma, the uncertainty of the
planetary area is about 14% and the planetary radius of 7%. The
planet's semi-major axis is derived from the measured period and
stellar mass, using Kepler's Thi