for Community Scientists
in the Ariel mission


18 June 2021

The purpose of this Announcement of Opportunity (AO) is to solicit the participation of the scientific community in the role of Community Scientist (CS) in the Ariel mission. This AO is open to scientists affiliated with institutes located in ESA Member States. Scientists involved in the Ariel Mission Consortium (AMC) (programmatic, scientific, or technical) management or being responsible for hardware or software development and procurement activities are not eligible to apply.

Ariel is the medium mission "M4" in ESA's Science Programme. Ariel will perform a chemical survey of a diverse sample of at least 500 exoplanets orbiting host stars with a range of spectral types. Most Ariel observations will consist of transit and/or eclipse spectroscopy of the atmospheres of warm and hot exoplanets, to address the following fundamental questions:

  • What are exoplanets made of?
  • How do planets and planetary systems form?
  • How do planets and their atmospheres evolve over time?


Community ScientistS

Through this AO, ESA aims to appoint up to five Community Scientists who will join the Ariel Science Team. Up to three Community Scientists are expected to cover science areas augmenting those of the Ariel Science Team (AST) members from the Ariel Mission Consortium and from international partners (e.g., they will have expertise in fields such as Solar System planetary science, data science, protoplanetary discs). A further two Community Scientists will be selected in scientific areas relevant for the Complementary Science programme. The main responsibility of the Community Scientists will be to advise ESA on the means to optimise the use of Ariel data by the general scientific community. This includes looking after the interests of the scientific community involved in the Ariel complementary science programmes. In addition, the Community Scientists will be expected to provide support to the communications activities of ESA.

The successful candidates will be appointed, ad personam, for an initial term of three years, which may be renewed.


Proposal Documentation

An invitation from the ESA Director of Science to respond to this Announcement of Opportunity can be found in the right-hand menu.

Full details of the appointment requirements and conditions, the contents and formats of the required Letter of Intent and the proposal, and the evaluation criteria are given in the AO document, available to download from the right-hand menu. Additional important information can be found in the Ariel Science Management Plan and the Definition Study Report, both of which are available to download from the right-hand menu.


Letter of Intent Submission

Letters of Intent, in PDF format, must be submitted using the Letter of Intent submission form linked below, before the deadline of 9 July 2021, 12:00 (noon) CEST.

Letter of Intent Submission Form
The deadline for receipt of proposals was 9 July 2021, 12:00 (noon) CEST


Proposal Submission

Proposals, in PDF format, must be submitted using the proposal submission form linked below, before the deadline of 31 August 2021, 12:00 (noon) CEST.

Proposal Submission Form
The deadline for receipt of proposals was 31 August 2021, 12:00 (noon) CEST



The schedule for this AO is given in the table below:


Date of AO release 18 June 2021
Due date for mandatory Letter of Intent 9 July 202112:00 (noon) CEST
Due date for proposals 31 August 2021, 12:00 (noon) CEST
Appointment of Community Scientists October 2021



Further queries should be addressed to:

Paul McNamara

Astronomy and Astrophysics Mission Coordinator
Directorate of Science
European Space Agency
Email: Paul.McNamara@esa.int


Last updated:31 August 2021


To be informed about new Announcements or Calls from the ESA Science Directorate please subscribe to the dsciannounce mailing list.