Planet Hunter I
The roster of known planets beyond our own solar system is closing in on 200 members. But a decade from now, it could well be closing in on two thousand -- thanks in large part to a single satellite.
The mission is called SIM-Planet Quest. It's scheduled for launch in 2011. It'll carry two or more telescopes mounted to a long support beam. Computers will combine the signals from the telescopes to produce a sharp view of the target star systems. With such clarity, astronomers can look for tiny "wobbles" in the positions of the stars caused by the gravity of orbiting planets.
Part of the SIM-Planet Quest time will be devoted to looking at a couple of thousand stars for fairly large, heavy planets. Scientists say this could yield hundreds of new planets. With a large sampling, astronomers can do a more thorough job of explaining how planets form, and how our own solar system compares to others.
A second phase of the mission will look at a few dozen of the closest stars for planets that are comparable in size and mass to Earth. So far, all the planets found around "normal" stars are big and heavy, and most are quite close to their parent stars. Such planets are not likely homes for life. Earth-like worlds are more difficult to find. But they present the best chance of finding life beyond the solar system.
Another mission will use a different technique to look for planets, and we'll talk about that tomorrow.
Script by Damond Benningfield, Copyright 2005
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