Exoplanets, -moons, -comets

The Next Frontier In Exoplanet Science: Imaging Our Neighbouring Planetary Systems

By Keith Cowing

Status Report

astro-ph.IM

December 19, 2025

Filed under astro-ph.IM, astronomy, ESO 2040 Expanding Horizons, exoplanet, Extremely Large Telescope, Habitable Worlds Observatory, imaging, LIFE mission, rocky exoplanet, Stellar Cartography

The Next Frontier In Exoplanet Science: Imaging Our Neighbouring Planetary Systems — A possible architecture for HWO under study by the HWO Technology Maturation Project Office. This design has an 8-meter inscribed diameter filled by 37 hexagonal segments — larger than JWST. Unlike JWST, this telescope is an off-axis format with a secondary mirror on a single strut structure at top and a multilayer deployable barrel for micrometeorite protection and thermal stability. — STSCI

Transmission and eclipse spectroscopy have been invaluable tools for the characterisation of extrasolar planet atmospheres. While they will continue to provide many new insights and discoveries in the decade(s) to come, these methods are running up against sources of stellar noise from stellar surface inhomogeneities and variability.

In this white paper we discuss how the next steps in the characterisation of small, temperate rocky planets requires high-contrast imaging, making the planetary systems around our closest neighbouring stars the new frontier in exoplanet science. The Extremely Large Telescopes (ELTs) will be at the forefront of this quest.

The Planetary Camera and Spectrograph (PCS) on ESO’s ELT and GmagAO-X on the GMT are planned to become operational in the 2035-2040 time-frame, allowing the characterisation of up to dozen(s) of rocky planets around nearby red dwarf stars.

We discuss what role there will be still to play for ground-based exoplanet characterisation in the era of the space-borne Habitable Worlds Observatory and LIFE missions.

Ignas Snellen, Sebastiaan Haffert, Matthew Kenworthy, Tomas Stolker

Comments: White Paper – ESO 2040 Expanding Horizons, 3 pages, no figures
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2512.13756 [astro-ph.IM] (or arXiv:2512.13756v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2512.13756
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Submission history
From: Ignas Snellen
[v1] Mon, 15 Dec 2025 10:21:35 UTC (117 KB)
https://arxiv.org/abs/2512.13756

Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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