Kepler's First Scientific Result

NASA's new planet-hunting Kepler space telescope has detected the changing phases and atmosphere of a planet a thousand light years away(the NASA figure above shows a comparison of ground-based and space-based light curves for hot exoplanet HAT P7b). This "hot Jupiter" exoplanet had already been detected with Earth-based measurements, but Kepler was able to measure a more precise light curve for the planet, allowing scientists to infer an atmospheric temperature (about 2400 C) and to determine that the planet's orbit is circular. This was intended as more of a calibration of Kepler's capabilities, but even at this early stage of the mission, it was able to return useful new information for this previously known exoplanet.

Kepler is looking at thousands of stars in a fixed region of space and will be able to measure similarly precise light curves for all of the stars it will be "staring at" for the next three years or more. A fraction of those stars are expected to have planets in orbital planes oriented to allow Kepler to detect the slight dimming of the stars' light as the planets pass in front of them.