Ariel - The ESA M4 Space Mission to Focus on the Nature Of Exoplanets

The ESA M4 mission Ariel, the atmospheric remote-sensing infrared exoplanet large-survey, has been adopted in 2020 within the Cosmic Vision science programme of ESA. The goal of Ariel is to investigate the atmospheres of planets orbiting distant stars in order to address the fundamental questions on how planetary systems form and evolve and to study in detail the composition of exoplanetary atmospheres. During its 4-year mission, Ariel will observe up to 1000 exoplanets -  building on (future) findings from space missions like PLATO, JWST, TESS, and CHEOPS - ranging from Jupiter- and Neptune-size down to super-Earth size, in a wide variety of environments, in the visible and the infrared. The main focus of the mission will be on warm and hot planets in orbits close to their star. Some of the planets may be in the habitable zones of their stars, however. The analysis of Ariel spectra and photometric data will allow to extract the chemical fingerprints of gases and condensates in the planets’ atmospheres, including the elemental composition for the most favourable targets. The Ariel mission has been developed by a consortium of more than 60 institutes from 15 ESA member state countries, including UK, France, Italy, Poland, Spain, the Netherlands, Belgium, Austria, Denmark, Ireland, Hungary, Sweden, Czech Republic, Germany, Portugal, with an additional contribution from NASA and CSA.