The ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) mission was selected on Wednesday as the next European Space Agency (ESA) science mission, putting UK leadership at the heart of research into planets that lie outside our solar system – exoplanets. Ariel will address fundamental questions on what exoplanets are made of and how planetary systems form and evolve by investigating the atmospheres of hundreds of planets orbiting different types of stars, enabling the diversity of properties of both individual planets as well as within populations to be assessed. Over the course of four years, the ARIEL spacecraft, will observe 1000 planets orbiting distant stars and marks the first large-scale survey of the chemistry of exoplanet atmospheres. Through our modern Industrial Strategy and record funding for R&D, increasing investment to around £12 billion by 2021, we will continue to do all we can to boost our world-leading science sector and build a Britain fit for the future.”

 ESA’s Science Programme Committee chose ARIEL for the fourth medium-class science mission (M4) in its Cosmic Vision Programme. It relies on the UK’s science and engineering expertise, which is at the forefront of the Government’s Industrial Strategy.”

 The mission’s Principal Investigator is Professor Giovanna Tinetti, from University College

 London, who will lead the mission science. “ARIEL will study a statistically large sample of exoplanets to give us a truly representative picture of what these planets are like. This will enable us to answer questions about how the chemistry of a planet links to the environment in which it forms, and how its birth and evolution are affected by its parent star.”

ARIEL will study a number of exoplanets – ranging from Jupiter- and Neptune-size planets down to so-called super-Earths – in a variety of environments, but will focus mainly on warm and hot planets in orbits close to their star. Ariel will use a metre-sized mirror and instrumentation designed to analyse, in visible and infrared light, the chemical make-up of the gases that shroud distant worlds, or exoplanets as they are known. Ariel will measure the chemical fingerprints of the atmospheres as the planet crosses in front of its host star, observing the amount of dimming at a precision level of 10–100 parts per million relative to the star.
The European Space Agency announces a mission to study the atmospheres of exoplanets. Selected as Cosmic Vision medium class M4 mission, ARIEL is expected to launch in 2028.