Related papers: A framework for evaluating biosignature potential …
Recent discoveries of potentially habitable exoplanets have ignited the prospect of spectroscopic investigations of exoplanet surfaces and atmospheres for signs of life. This chapter provides an overview of potential surface and temporal…
Understanding the climates of terrestrial exoplanets and the detectability of biosignatures is an inherently interdisciplinary challenge, requiring the integration of insights from Solar System exploration, exoplanet observations and…
Recent discoveries imply that Early Mars was habitable for life-as-we-know-it; that Enceladus might be habitable; and that many stars have Earth-sized exoplanets whose insolation favors surface liquid water. These exciting discoveries make…
An important future goal in exoplanetology is to detect and characterize potentially habitable planets. Using nulling interferometry, LIFE will allow us to constrain the radius and effective temperature of (terrestrial) exoplanets, as well…
Methane has been proposed as an exoplanet biosignature. Imminent observations with the James Webb Space Telescope may enable methane detections on potentially habitable exoplanets, so it is essential to assess in what planetary contexts…
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…
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…
Detection of life on other planets requires identification of biosignatures, i.e., observable planetary properties that robustly indicate the presence of a biosphere. One of the most widely accepted biosignatures for an Earth-like planet is…
In order to assess observational evidence for potential atmospheric biosignatures on exoplanets, it will be essential to test whether spectral fingerprints from multiple gases can be explained by abiotic or biotic-only processes. Here, we…
Modeling the detection of life has never been more opportune. With next generation space telescopes, like the currently developing Habitable Worlds Observatory (HWO) concept, we will begin to characterize rocky exoplanets potentially…
Photosynthesis is an ancient metabolic process that began on the early Earth, offering plentiful energy to organisms that utilize it, to the extent that they can achieve global significance. The potential exists for similar processes to…
The key goals of the astrobiology community are to identify environments beyond Earth that may be habitable, and to search for signs of life in those environments. A fundamental aspect of understanding the limits of habitable environments…
Executive Summary: The Habitable Worlds Observatory (HWO) is the first astrophysics flagship mission with a key cross-divisional astrobiology science goal of searching for signs of life on rocky planets beyond our solar system. The Living…
Some sub-Neptune planets may host habitable conditions; for example "Hycean" worlds with H2 envelopes over liquid water oceans can maintain potentially hospitable pressures and temperatures at their surface. Recent JWST observations of…
In the modern search for life elsewhere in the Universe, we are broadly looking for the following: the planets similar to Earth - physical indicators of habitability, and the manifestation of life - the biological signatures. A biosignature…
The first potential exoplanet biosignature detections are likely to be ambiguous due to the potential for false positives: abiotic planetary processes that produce observables similar to those anticipated from a global biosphere. Here we…
Motility is a ubiquitous feature of microbial life on Earth, and is widely regarded as a promising biosignature candidate. In the search for motile organisms, it is therefore valuable to have rough estimates for the number of such microbes…
This study aims to identify exemplary science cases for observing N$_2$O, CH$_3$Cl, and CH$_3$Br in exoplanet atmospheres at abundances consistent with biogenic production using a space-based mid-infrared nulling interferometric…
Context. Homochirality is a generic and unique property of life on Earth and is considered a universal and agnostic biosignature. Homochirality induces fractional circular polarization in the incident light that it reflects. Because this…
Planetary surface habitability has so far been considered, in the main, upon a global scale. The increasing number of 3D modelling studies of (exo)planetary climate has highlighted the need for a more nuanced understanding of surface…