The Kepler Telescope and The search For Earth Like Planets

The Kepler telescope is looking for other Earth-like planets. The Kepler telescope was launched into space on March 6, 2009, and will search for Earth-like planets. It does this by looking for regular dips in the brightness of stars. Planets pass between their star and the telescope, blocking out a small amount of the light. The size of the dip tells us about the size of the planet. The time between dips tells us how far away the planet is from its star.
The mission, by NASA’s estimates, will cost about $600 million dollars. This is the same mission that the president considered too expensive to fund last year (2008), but later put it back into place because he thought it was important (2009).

The Kepler mission is the most important and exciting thing NASA has done in years.
The mission will search for planets like Earth: planets like ours, close enough to their star to support life, and with liquid water. The Kepler telescope will look at a patch of sky containing about 100,000 stars. It will stare at each star for months at a time, searching for planets that are passing between us and the star.
A planet passing in front of its star causes the star to dim ever so slightly. This is called a transit. By looking for these tiny fluctuations in light, Kepler will be able to find planets as small as Earth. And it will be able to find hundreds or thousands of them, not just one or two.