Google climbs aboard search for ET planets

Stan Beer
Thursday, 20 March 2008 13:31

Your IT - Home IT

No stranger to the science of mapping and organising the world's vast volumes of data, search kingpin Google has joined an MIT project to map the heavens from a satellite and search for planets like Earth. Researchers claim the project could rapidly discover hundreds of planets similar to Earth, something which has eluded scientists until now.

Google has provided a seed grant to fund development of six wide-field high resolution digital cameras to be placed aboard a satellite-based observatory under design called the Transiting Exoplanet Survey Satellite (TESS), which could launched by 2012 depending on funding. The observatory will search for planets outside the solar system that appear to cross in front of bright stars.

According to the MIT report, Google wants to work on the development of ways of sifting through the huge volume of data that will be generated by the satellite to find useful information.

Most searches so far depend on the gravitational attraction that planets exert on their stars in order to detect them, and therefore are best at finding large planets that orbit close to their stars. So far, most of the 200 plus planets discovered outside our solar system are much larger than Earth.

TESS, however, would search for stars whose orbits as seen from Earth carry them directly in front of the star, obscuring a tiny amount of starlight. Some ground-based searches have used this method and found about 20 planets so far, but a space-based search could detect much smaller, Earth-sized planets, as well as those with larger orbits.

This transit-detection method, by measuring the exact amount of light obscured by the planet, can pinpoint the planet's size. When combined with spectroscopic follow-up observations, it can determine the planet's temperature, probe the chemistry of its atmosphere, and perhaps even find signs of life, such as the presence of oxygen in the air.

According to MIT researchers, two years after launch, the cameras - which have a total resolution of 192 megapixels - will cover the whole sky, getting precise brightness measurements of about two million stars in total. In that time, the scientists expect to have found at least a thousand planetary systems and up to 10 times as many planets.