ESA’s Ariel mission will study about 1000 exoplanets in much more detail than ever before

Launching in 2029, the European Space Agency’s Ariel spacecraft, short for Atmospheric Remote-sensing Infrared Exoplanet Large-survey, will perform a large-scale survey of exoplanets – planets outside our solar system.

Ariel will observe about 1000 exoplanets, ranging from rocky planets to gas giants and study their nature, both as individuals and as populations, whilst monitoring the activity of their host stars. It is the first mission dedicated to measuring the chemical make-up and atmospheric temperature profiles of hundreds of exoplanets.

The spacecraft will detect signs of well-known ingredients in the planets’ atmospheres, including water vapour, carbon dioxide and methane. It will also detect exotic metallic compounds to decipher the overall chemical environment of the distant star system.

“Although astronomers have discovered many exoplanets in recent years, they still have not found a clear link between the characteristics of an exoplanet and those of its parent star. To do this, the study of exoplanets has to shift from ‘discovering’ towards ‘studying and understanding’. A large-scale survey of exoplanets is required – Ariel’s key objective is to perform such a survey, says the mission factsheet.

We know that greenhouse gases in a planet’s atmosphere impact life on the surface.Planned for launch in 2029, @ESAArielMission will measure gases like #CarbonDioxide and methane to discover more about ∼1000 exoplanets.More in our new factsheet? pic.twitter.com/sMS44o8tFW

— ESA Science (@esascience) August 18, 2022

Ariel will consist of a Cassegrain reflector telescope, an infrared spectrometer called AIRS (Ariel medium-resolution InfraRed Spectrometer) and a Fine Guidance System (FGS) module.

The spacecraft is expected to launch on an Ariane 62, together with ESA’s Comet Interceptor mission and its final destination is the Lagrange point 2 (also known as L2), 1.5 million kilometres beyond Earth in the direction away from the Sun.

The mission has a nominal four-year operational timeline, with a potential extended science operations phase lasting a further two years.