Free Astronomy Magazine May-June 2018

34 MAY-JUNE 2018 SPACE CHRONICLES ESA chooses ARIEL as its future medium-size space mission by IAC T he European Space Agency (ESA) has just announced that its next medium-size scientific mission will be ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large survey). The project will have a useful lifetime of four years in space and its launch is scheduled for 2028. While it remains in orbit, it will observe around 1,000 planets and carry out the first large scale study of the chemistry of the atmospheres of these exoplanets. “This mission will enable the systematic study of the formation and evolution of exo- planets, particularly their atmos- pheres” , explains Enric Pallé, an IAC researcher and one of the partici- pants in this project. He continues, “ARIEL will study earthlike planets, but hot ones” , in other words, those that orbit close to their star. ARIEL was developed by a consor- tium of more than 60 institutes from 15 ESA countries, including the United Kingdom, France, Italy, Poland, Spain, The Netherlands, Belgium, Austria, Denmark, Ireland, Hungary, Sweden, Germany, and Portugal, with the further collabora- tion of NASA. The IEEC (Institut d’Es- tudis Espacials de Catalunya) heads the Spanish participation. Apart from its scientific contribu- tion, it is participating in the build- ing of the mission, including the satellite’s electronic system, which controls the telescope and move- ments of the secondary mirror, as well as the computer programs that schedule the observations of planets and are used in ESA ground control. The other Spanish institutions in- volved in the project are the Astro- biology Centre of the Polytechnic University of Madrid and the Insti- tuto de Astrofísica de Canarias (IAC). “Although, so far, we’ve discovered around 3800 planets orbiting other stars, the nature of these exoplanets remains very mysterious” , comments Ignasi Ribas, an astrophysicist at IEEC-CSIC and Principal Investigator of ARIEL in Spain. He adds: “ARIEL will study a sample that is statisti- A rtist’s impression of ARIEL on its way to Lagrange Point 2 (L2). [ESA/STFC RAL Space/UCL/ Europlanet-Science Office]