First Light for Kepler

Kepler, the planet-hunting satellite, has sent back its first light image —  a 100-square-degree patch of sky that contains a star cluster called NGC 6791. This is only a part of Kepler’s full field of view, but even from this image, it’s clear that Kepler has pretty good eyesight.

The Kepler spacecraft is equipped with a telescope and photometer, and is out there looking for planets like Earth and will be on the  hunt for the next 3.5 years.  It is focused on 100,000 pre-selected stars — and will continuously study their light output to watch for periods when these stars look a bit dimmer.  Such dips in brightness will be a very good indication that planets are crossing in front of the star, blocking out some of the light from their parent stars.

Kepler needs a very precise view to do this — and to be able to spot planets as small as Earth, the images are intentionally blurred slightly. This minimizes the number of saturated stars. Saturation, or “blooming,” occurs when the brightest stars overload individual pixels, causing the signal to spill out into nearby pixels.

The mission scientists and technicians for Kepler are now in a period of calibration and engineering testing, which will help astronomers tweak the focus and adjust its onboard instruments.  When that work is done, the serious work of planet-hunting will get started. It’s going to be a very exciting time for planet-hunters, who are already jazzed by the numbers of planets already found. But, Kepler gives them the chance to seek out Earth-type worlds — and who knows what they’ll find.  Stay tuned!