Artist's impression of CHEOPS, the characterising exoplanets satellite, with an exoplanet system in the background
Artist's impression of CHEOPS, the characterising exoplanets satellite, with an exoplanet system in the background
In reality, the CHaracterising ExOPlanets Satellite (CHEOPS) will be located in Earth orbit and will study exoplanet systems from a distance, accurately measuring the size of the planets as they pass in front of their host star. These measurements, combined with information about the mass of the planet based on separate observations, will enable the density of the planets to be estimated. This will place limits on the possible composition and structure of the planets and show, for example, whether they are predominantly rocky or gaseous, or whether they might be home to significant oceans. CHEOPS will focus in particular on bright stars that host Earth to Neptune-sized planets. The characterisation of these worlds – many of them without equivalents of the Solar System – is a critical part of understanding the formation, origin and evolution of exoplanets in this size range.
