Related papers: Surface and Temporal Biosignatures
The detection and characterization of potentially habitable exoplanets is one of the chief goals of astrophysics for the coming decades. Imaging in reflected light is well suited for characterizing Earth-like planets, as much can be learned…
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…
A long-term goal of exoplanet studies is the identification and detection of biosignature gases. Beyond the most discussed biosignature gas O$_2$, only a handful of gases have been considered in detail. Here we evaluate phosphine (PH$_3$).…
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…
The current goals of the astrobiology community are focused on developing a framework for the detection of biosignatures, or evidence thereof, on objects inside and outside of our solar system. A fundamental aspect of understanding the…
Technological civilizations may rely upon large-scale photovoltaic arrays to harness energy from their host star. Photovoltaic materials, such as silicon, possess distinctive spectral features, including an "artificial edge" that is…
The upcoming extremely large telescopes will provide the first opportunity to search for signs of habitability and life on non-transiting terrestrial exoplanets using high-contrast, high-resolution instrumentation. However, the suite 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 detection of massive planets orbiting nearby stars has become almost routine, but current techniques are as yet unable to detect terrestrial planets with masses comparable to the Earth's. Future space-based observatories to detect…
An increasing number of potentially habitable terrestrial planets and planet candidates are found by ongoing planet search programs. The search for atmospheric signatures to establish planetary habitability and the presence of life might be…
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…
Searching for signs of life is a primary goal of the Habitable Worlds Observatory (HWO). However, merely detecting oxygen, methane, or other widely discussed biosignatures is insufficient evidence for a biosphere. In parallel with…
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…
Exoplanet characterization missions planned for the future will soon enable searches for life beyond our solar system. Critical to the search will be the development of life detection strategies that can search for biosignatures while…
The discovery of inhabited exoplanets hinges on identifying biosignature gases. JWST can reveal biosignature gases, though current discoveries have yet to evidence life. The central challenge is attribution: how can we confidently identify…
The goals of the astrobiology community are focussed on developing a framework for the detection of biosignatures, or evidence thereof, on objects inside and outside of our solar system. A fundamental aspect of understanding the limits of…
A habitable exoplanet is a world that can maintain stable liquid water on its surface. Techniques and approaches to characterizing such worlds are essential, as performing a census of Earth-like planets that may or may not have life will…
The so-called Vegetation Red-Edge (VRE), a sharp increase in the reflectance around $700 nm$, is a characteristic of vegetation spectra, and can therefore be used as a biomarker if it can be detected in an unresolved extrasolar Earth-like…
Next-generation space observatories will conduct the first systematic surveys of terrestrial exoplanet atmospheres and search for evidence of life beyond Earth. While in-depth observations of the nearest habitable worlds may yield enticing…
This article reviews the emerging field of exo-geoscience, focusing on the geological and geophysical processes thought to influence the evolution and (eu)habitability of rocky exoplanets. We examine the possible roles of planetary…