ARIEL

The Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL) is a space telescope and the fourth medium-class mission of the European Space Agency's Cosmic Vision programme. The mission is aimed at observing at least 1000 known exoplanets using the transit method, studying and characterising the planets' chemical composition and thermal structures. Compared to the James Webb Space Telescope, ARIEL will have more observing time available for planet characterisation but a much smaller telescope and it will be launched almost a decade later. ARIEL is expected to be launched in 2029 aboard an Arianespace Ariane 6 together with the Comet Interceptor. Mission ARIEL will observe 1000 planets orbiting distant stars and make the first large-scale survey of the chemistry of exoplanet atmospheres. The objective is to answer fundamental questions about how planetary systems form and evolve. A spectrometer will spread the light into a spectrum ("rainbow") and determine the chemical fingerprints of gases in the planets' atmospheres. This will enable scientists to understand how the chemistry of a planet links to the environment in which it forms, and how its formation and evolution are affected by its parent star. ARIEL will study a diverse population of exoplanets in a wide variety of environments, but it will focus on warm and hot planets in orbits close to their star. The ARIEL mission is being developed by a consortium of various institutions from eleven member states of the European Space Agency (ESA), and international contributors from four countries. The project is led by principal investigator Giovanna Tinetti of the University College London, who had previously led the unsuccessful Exoplanet Characterisation Observatory (EcHO) proposal for the M3 Cosmic Vision launch slot. Operations of the mission and the spacecraft will be handled jointly by ESA and the consortium behind the mission's development, through a coordinated Instrument Operations and Science Data Centre (IOSDC). A Mission Operations Centre (MOC) will be set up at the European Space Operations Centre (ESOC) in Darmstadt, Germany, while a concurrent ARIEL Science Operations Centre (SOC) will be set up at the European Space Astronomy Centre (ESAC) near Madrid, Spain. The MOC will be responsible for the spacecraft itself, while the SOC will be responsible for archiving mission data and scientific data downlinked from the spacecraft.