Planet Hunt

Scientists hope to get an insight into the planets of neighboring solar systems when the COROT satellite launches on Wednesday at 1423 GMT from Kazakhstan. A project of the French National Space Studies Center (CNES) in which the European Space Agency (ESA) is participating, COROT will send into orbit a telescope capable of detecting smaller, rocky planets that could support life. The mission is a milestone in the search for a second Earth, Heike Rauer said in an interview with DW-WORLD.DE.

DW-WORLD: The European Space Agency (ESA) has called COROT a unique astronomical mission. What is so special about this project?

Heike Rauer: For the first time, the COROT satellite will look from space for planets that don't orbit our sun, but instead circle other stars in other solar systems. We hope, with COROT, to find rocky planets close to a star. Until now, these planets have not been found, but we believe they exist. The research will hopefully discover a second Earth.

Can COROT find planets that are similar to Earth?

COROT finds planets by measuring changes in brightness. It observes a star from a certain point and if a planet passes within its orbit between the star and the satellite, the brightness changes and COROT measures that. One can think of it as similar to a lunar eclipse. Since COROT will only spend five months looking at a certain area, it is unlikely that it will see another Earth. An Earth-like planet would need an entire year to orbit around the star and then would come only one time in the year past the point that the satellite is watching. We will not likely find a second earth, but rather other planets, that are closer to the stars, where the orbiting period is shorter.

Could people live on these planets?

If the star these planets orbit around is as hot as our sun, it would be uninhabitable for humans, because the temperatures on the planet would be so high. But there are also so-called M Stars, which are not as hot. The planets that orbit around these stars are much cooler and could support life. When COROT finds such planets, it would naturally be extremely exciting. COROT cannot recognize whether there's life on these planets or whether life would be possible there. To find this out, one must examine the atmosphere and look for molecules such as water, ozone or oxygen.

Can COROT's findings be trusted or does it only provide a basis for information?

COROT measures the changes in the brightness of stars, which could have a variety of causes. Naturally, we hope that a change in brightness is produced by a planet. It could be that the star has spots or that it's not a star and a planet, but rather two stars crossing each other. To start out, the scientists must figure out what caused the crop in brightness. One cannot hope that COROT will immediately begin discovering terrestrial planets. The scientists will only announce they've found a planet if they're sure.