Find out how Cheops, the Characterising Exoplanet Satellite, is going to investigate distant planets orbiting stars other than the Sun to discover what these alien worlds are made of. As part of its inspiring mission, Cheops will measure accurately the dimensions of small exoplanets – in the Earth- to Neptune-size range – of which we already know the mass in order to determine their densities. It will also observe hot Jupiter planets orbiting close to their parent stars to learn more about their atmosphere, and identify interesting targets for in-depth observations by future missions.Cheops is a partnership between ESA and Switzerland, with a dedicated consortium led by the University of Bern, and with important contributions from Austria, Belgium, France, Germany, Hungary, Italy, Portugal, Spain, Sweden and the UK.

Launch is scheduled for 17 December from Europe’s Spaceport in Kourou, French Guiana.

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