English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The conventional observables to identify a habitable or inhabited environmentin exoplanets, such as an ocean glint or abundant atmospheric O$_2$, will bechallenging to detect with present or upcoming observatories. Here we suggest anew signature. A low carbon abundance in the atmosphere of a temperate rockyplanet, relative to other planets of the same system, traces the presence ofsubstantial amount of liquid water, plate tectonic and/or biomass. We show thatJWST can already perform such a search in some selected systems like TRAPPIST-1via the CO$_2$ band at $4.3\,\rm \mu m$, which falls in a spectral sweet spotwhere the overall noise budget and the effect of cloud/hazes are optimal. Wepropose a 3-step strategy for transiting exoplanets: 1) detection of anatmosphere around temperate terrestrial planets in $\sim 10$ transits for themost favorable systems, (2) assessment of atmospheric carbon depletion in $\sim40$ transits, (3) measurements of O$_3$ abundance to disentangle between awater- vs biomass-supported carbon depletion in $\sim100$ transits. The conceptof carbon depletion as a signature for habitability is also applicable fornext-generation direct imaging telescopes.

Atmospheric carbon depletion as a tracer of water oceans and biomass on temperate terrestrial exoplanets