Related papers: On detecting biospheres from chemical thermodynami…
Chemical disequilibrium in planetary atmospheres has been proposed as a generalized method for detecting life on exoplanets through remote spectroscopy. Among solar system planets with substantial atmospheres, the modern Earth has the…
Chemical disequilibrium in exoplanetary atmospheres (detectable with remote spectroscopy) can indicate life. The modern Earth's atmosphere-ocean system has a much larger chemical disequilibrium than other solar system planets with…
Robust exoplanet characterization studies are underway, and the community is looking ahead toward developing observational strategies to search for life beyond our solar system. With the development of life detection approaches like…
Chemical disequilibrium quantified via available free energy has previously been proposed as a potential biosignature. However, exoplanet biosignature remote sensing work has not yet investigated how observational uncertainties impact the…
Chemical disequilibrium has recently become a relevant topic in the study of the atmospheres of of transiting extrasolar planets, brown dwarfs, and directly imaged exoplanets. We present a new way of assessing whether or not a Jovian-like…
The near-term capability to characterize terrestrial exoplanet atmospheres may bring us closer to discovering alien life through atmospheric data. However, remotely detectable candidate biosignature gases are subject to false positive…
The detection of strong thermochemical disequilibrium in the atmosphere of an extrasolar planet is thought to be a potential biosignature. In this article we present a new kind of false positive that can mimic a disequilibrium or any other…
Warm rocky exoplanets within the habitable zone of Sun-like stars are favoured targets for current and future missions. Theory indicates these planets could be wet at formation and remain habitable long enough for life to develop. In this…
The search for life on planets outside our solar system will use spectroscopic identification of atmospheric biosignatures. The most robust remotely-detectable potential biosignature is considered to be the detection of oxygen (O_2) or…
The chemical composition of the earths atmosphere far from equilibrium is unique in the solar system and has been attributed to the presence of widespread life. Here I show that this perspective can be quantified using non-equilibrium…
We have developed a 1D planetary atmosphere model that solves in a self-consistent manner the evolution of temperature and disequilibrium chemistry in the vertical direction. Thermochemical kinetics is based on a reaction network built from…
Some atmospheric gases have been proposed as counter indicators to the presence of life on an exoplanet if remotely detectable at sufficient abundance (i.e., antibiosignatures), informing the search for biosignatures and potentially…
Biosignature gas detection is one of the ultimate future goals for exoplanet atmosphere studies. We have created a framework for linking biosignature gas detectability to biomass estimates, including atmospheric photochemistry and…
Current investigations of exoplanet biosignatures have focused on static evidence of life, such as the presence of biogenic gases like O2 or CH4. However, the expected diversity of terrestrial planet atmospheres and the likelihood of both…
One of the prime goals of future investigations of extrasolar planets is to search for life as we know it. The Earth's biosphere is adapted to current conditions. How would the atmospheric chemistry of the Earth respond if we moved it to…
The atmospheres of small exoplanets likely derive from a combination of geochemical outgassing and primordial gases left over from formation. Secondary atmospheres, such as those of Earth, Mars and Venus, are sourced by outgassing.…
Oxygen is a well-studied biosignature. Studying potential abiotic pathways for O2 build-up in exoplanet atmospheres is essential for evaluating whether the detection of O2 would constitute a biosignature detection on other worlds. Previous…
The search for potentially habitable exoplanets centers on detecting biosignature molecules in Earth-like atmospheres, which makes it essential to understand their detectability under biologically and geologically influenced conditions. In…
The search for life on exoplanets is one of the grand scientific challenges of our time. The strategy to date has been to find (e.g., through transit surveys like Kepler) Earth-like exoplanets in their stars habitable zone, then use…
Ocean-atmosphere chemistry on Earth has undergone dramatic evolutionary changes through its long history, with potentially significant ramifications for the emergence and long-term stability of atmospheric biosignatures. Though a great deal…