CHaracterising ExOPlanet Satellite:
ESA’s CHaracterising ExOPlanet Satellite (CHEOPS) recently revealed a four-planet system whose outermost world is a small and rocky planet — not a gas giant.
- It is a European Space Agency (ESA) spacecraft.
- It is the first space mission dedicated to studying bright, nearby stars that are already known to host exoplanets, in order to make high-precision observations of the planet’s size as it passes in front of its host star.
- It focuses on planets in the super-Earth to Neptune size range.
- Orbit: Sun-synchronous, dusk-dawn orbit at 700 km above Earth.
- The spacecraft has a single science instrument: a specialized camera called a photometer.
- CHEOPS observes transits of Earth-to-Neptune-sized exoplanets and measures their diameters.
- When combined with mass data from ground telescopes, it helps calculate planet density.
- A planet’s density provides vital clues about its composition and structure, indicating, for example, if it is predominantly rocky or gassy, or perhaps harbours significant oceans.
