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ARIEL In A Nut-shell​​​



ESA and Airbus have signed a contract to move forward with the design and construction of the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, Ariel, planned for launch in 2029

See the news release: Airbus will build ESA’s Ariel exoplanet satellite .


Ariel adoption: The ESA Science Programme Committee (SPC) has adopted Ariel in the meeting held on 12 November 2020. The mission adoption was the last study phase milestone before proceeding to mission implementation.

See the news release: Ariel moves from blueprint to reality.

Ariel is the M4 (4th medium-sized) mission in the ESA Cosmic Vision longterm plan. Ariel was selected in March 2018 and has now completed phase B1 (the definition study phase). The final study phase milestone was Mission Adoption achieved on 12 November 2020. After the succesful adoption the actual mission implementation will commence in 2021, with a planned launch by an Ariane 62 launcher in 2029 for a nominal 4 year mission, with a possible extension to 6 years.

The objective of Ariel is to perform a chemical sensus of a large (of order 1000) well selected diverse sample of primarily warm and hot exoplanets orbiting relatively nearby host stars with a range of spectral types from A to M. The key science questions Ariel will address are:

  • What are the physical processes shaping planetary atmospheres?
  • What are exoplanets made of?
  • How do planets and planetary systems form and evolve?

The target selection will be made before launch based on ESA science team and community inputs, and can be updated throughout the mission. The mission will deliver a homogeneous catalogue of planetary spectra, yielding refined molecular abundances, chemical gradients and atmospheric structure; diurnal and seasonal variations; presence of clouds and measurement of albedo.

Ariel will perform observations in three photometric bands (0.5-0.6 micron, 0.6-0.8 micron, and 0.8-1.1 micron) and three spectroscopic bands (1.1-1.95 micron (R>15), 1.95-3.9 micron (R>100), and 3.9-7.8 micron (R>30)) simultaneously covering the 0.5-7.8 micron spectral range, with an off-axis Cassegrain telescope having a 1.1x0.7 m primary providing a collecting area of 0.61 m2.

Ariel is a collaboration between ESA and the Ariel Mission Consortium (AMC - consisting of more than 50 institutes in 17 European countries and with NASA/JPL participation) which is responsible for the provision of the entire Ariel paylod module. After launch operations will be conducted jointly by ESA (mission operations & part of the science operations) an the AMC (part of the science operations) with the spacecraft in a large halo orbit around L2.

All aspects of the Ariel mission as adopted on 12 November 2020 are described in detail in the Red Book, which is available on the Documents and Articles webpage together with additional material.

Also, check out the presentations from the ARIEL: Science, Mission & Community 2020 conference held on 14-16 January 2020 in ESA/ESTEC, Noordwijk, The Netherlands.