Next Friday, NASA will launch a historic mission to try to answer a fundamental question: are there other worlds like Earth ?
A rocky planet like Earth reflects very little light into space. But there is a way to detect it: to identify the shadow it forms as it passes in front of its star . This transit causes a deviation of light that can last between two and six hours, and allows us to deduce data such as the size of the planet, its orbit and its temperature. In short, everything you need to know if it is potentially habitable .
The new Kepler space observatory to be launched by NASA this week has a very powerful differential photometer that makes it possible to continuously and simultaneously monitor the brightness of 100,000 dwarf stars , the most likely to sustain a planet like ours. "The inventory of planets that Kepler must carry out will be of great importance for understanding the frequency of planets in the same size category as Earth in our galaxy (the Milky Way)," explained Jon Morse, director of the division of astrophysics of the North American space agency.
NASA named the Kepler telescope after the 17th-century German astronomer Johannes Kepler, who discovered that the planets revolve around the Sun in ellipses and not in perfect circles.
You can follow the day-to-day of the mission through the web http://kepler.nasa.gov/ or via twitter.
