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

Previous research has indicated that high amounts of ozone (O3) and oxygen(O2) may be produced abiotically in atmospheres with high concentrations ofCO2. The abiotic production of these two gases, which are also characteristicof photosynthetic life processes, could pose a potential "false-positive" forremote-sensing detection of life on planets around other stars.We show herethat such false positives are unlikely on any planet that possesses abundantliquid water, as rainout of oxidized species onto a reduced planetary surfaceshould ensure that atmospheric H2 concentrations remain relatively high, andthat O2 and O3 remain low. Our aim is to determine the amount of O3 and O2formed in a high CO2 atmosphere for a habitable planet without life. We use aphotochemical model that considers hydrogen (H2) escape and a detailed hydrogenbalance to calculate the O2 and O3 formed on planets with 0.2 of CO2 around theSun, and 0.02, 0.2 and 2 bars of CO2 around a young Sun-like star with higherUV radiation. The concentrations obtained by the photochemical model were usedas input in a radiative transfer model that calculated the spectra of themodeled planets. The O3 and O2 concentrations in the simulated planets areextremely small, and unlikely to produce a detectable signature in the spectraof those planets. We conclude that with a balanced hydrogen budget, and forplanets with an active hydrological cycle, abiotic formation of O2 and O3 isunlikely to create a possible false positive for life detection in either thevisible/near-infrared or mid-infrared wavelength regimes.

Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres