Atmospheric characterization of terrestrial exoplanets in the mid-infrared: biosignatures, habitability & diversity

TL;DR

This paper advocates for a large space-based mid-infrared mission to characterize terrestrial exoplanet atmospheres, aiming to detect biosignatures, assess habitability, and explore atmospheric diversity, surpassing current capabilities.

Contribution

It proposes a dedicated ESA-led large MIR exoplanet mission, highlighting its scientific potential and outlining a development roadmap to enable atmospheric characterization of terrestrial exoplanets.

Findings

MIR observations can identify biosignatures and habitability indicators.

A large space mission can significantly advance exoplanet atmospheric studies.

International collaboration and technology development are crucial for mission success.

Abstract

Exoplanet science is one of the most thriving fields of modern astrophysics. A major goal is the atmospheric characterization of dozens of small, terrestrial exoplanets in order to search for signatures in their atmospheres that indicate biological activity, assess their ability to provide conditions for life as we know it, and investigate their expected atmospheric diversity. None of the currently adopted projects or missions, from ground or in space, can address these goals. In this White Paper we argue that a large space-based mission designed to detect and investigate thermal emission spectra of terrestrial exoplanets in the MIR wavelength range provides unique scientific potential to address these goals and surpasses the capabilities of other approaches. While NASA might be focusing on large missions that aim to detect terrestrial planets in reflected light, ESA has the opportunity to take leadership and spearhead the development of a large MIR exoplanet mission within the scope of the "Voyage 2050" long-term plan establishing Europe at the forefront of exoplanet science for decades to come. Given the ambitious science goals of such a mission, additional international partners might be interested in participating and contributing to a roadmap that, in the long run, leads to a successful implementation. A new, dedicated development program funded by ESA to help reduce development and implementation cost and further push some of the required key technologies would be a first important step in this direction. Ultimately, a large MIR exoplanet imaging mission will be needed to help answer one of mankind's most fundamental questions: "How unique is our Earth?"