ESA’s new small satellite will study super-Earths
22 October 2012
Studying planets around other stars will be the focus of a new small Science Programme mission led by the European Space Agency. The mission is due to launch in 2017.
Cheops (CHaracterising ExOPlanets Satellite) will target nearby, bright stars already known to have planets orbiting around them. Through high-precision monitoring of the star’s brightness, scientists will search for the tell-tale signs of a ‘transit’ as a planet passes briefly across its face.
In turn, this will allow an accurate measurement of the radius of the planet. For those planets with a known mass, the density will be revealed, providing an indication of the internal structure.
These key parameters will help scientists to understand the formation of planets from a few times the mass of the Earth – ‘super-Earths’ – up to Neptune-sized worlds.
It will also identify planets with significant atmospheres and constrain the migration of planets during the formation and evolution of their parent systems.
Cheops is the first of a possible new class of small missions to be developed as part of ESA’s Science Programme. It will operate in a Sun-synchronous low-Earth orbit at an altitude of 800km, and has a planned mission lifetime of 3.5 years.