The aim of the Expanding Horizons process is for ESO to gather input from the community to decide on its next major programme, following the completion of ELT construction. ESO has now formally opened the call for Letters of Intent (LoI) for the Expanding Horizons process with deadline 1 December 2026. The submission of a LoI is a requirement for submitting a proposal.
ESO Opens a Call for Letters of Intent for Expanding Horizons
Published: 30 Sep 2026
The LoI will be used to help ESO plan for internal resource needs and to assess whether the Senior Science Committee has a suitable composition. The Letter of Intent will not be used in the evaluation process but if a proposed concept is clearly inconsistent with the aims of the Expanding Horizons process, ESO will communicate this to the LoI submitters.
Detailed instructions are available for submitting a LoI.