

Earth’s spectrum over time (right panel), reproduced from [11]. The biosignature gases present change dramatically from epoch to epoch (left panel), producing significantly different spectra. The simultaneous detection of O2 at 0.8 µm with H2O, CH4, and CO2 at >0.8 µm demonstrates the presence of life in the modern Earth spectrum shown in the bottom right panel, but for habitable planets without much evidence of oxygenic biosignatures (e.g. Proterozoic and Archean Earth), coverage beyond 0.8 µm will be key to capture H2O, and CH4 features. — astro-ph.IM
The detection of life on rocky exoplanets in the habitable zones of nearby stars would be a paradigm-shifting advance, and it is one of the greatest scientific challenges of our time. There is no single spectral feature that is an unambiguous sign of life on a given exoplanet.
Instead, the current state-of-the-art approach involves detecting multiple molecular atmospheric features that should not exist together in equilibrium, e.g. simultaneous detection of O2 and CH4. Spectra across a wide wavelength (0.3-1.7 μm) range are necessary to cover multiple spectral features per molecule of interest and to contextualise the suite of molecular features detected.
While the US will lead the optical arm of the Habitable Worlds Observatory (HWO) coronagraph, a UK-led contribution of a near-infrared Integral Field Spectrograph (IFS) for the infrared arm will ensure UK leadership in the flagship scientific goal of HWO – to search for signatures of life on potentially habitable exoplanets.
Beth Biller, Dan Dicken, Olivier Absil, Raziye Artan, Jo Barstow, Jayne Birkby, Christophe Dumas, Sasha Hinkley, Tad Komacek, Katherine Morris, Lorenzo Pino, Sarah Rugheimer, Colin Snodgrass, Stephen Todd, Vinooja Thurairethinam, Amaury Triaud
Comments: White paper submitted to the UK Space Agency’s initiative “UK Space Frontiers 2035” this https URL
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2603.09321 [astro-ph.IM] (or arXiv:2603.09321v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2603.09321
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Submission history
From: Beth Biller
[v1] Tue, 10 Mar 2026 07:54:31 UTC (1,344 KB)
https://arxiv.org/abs/2603.09321
Astrobiology, Exoplanet, Astronomy,






