Related papers: Subsurface Exolife
The study of origins of life on Earth and the search for life on other planets are closely linked. Prebiotic chemical scenarios can help prioritize planets as targets for the search for life as we know it and can provide informative priors…
The recent discovery of a staggering diversity of planets beyond the Solar System has brought with it a greatly expanded search space for habitable worlds. The Kepler exoplanet survey has revealed that most planets in our interstellar…
Theory and observation for the search for life on exoplanets via atmospheric "biosignature gases" is accelerating, motivated by the capabilities of the next generation of space- and ground-based telescopes. The most observationally…
Studying the habitability, internal structure and composition of exoplanets is crucial for understanding their potential to sustain life beyond our solar system. Characterizing planetary structures and atmospheric evolution provides…
'Most habitable worlds in the cosmos will have no remotely detectable signs of life' is proposed as a biological hypothesis to be tested in studies of exoplanets. Habitable planets could be discovered elsewhere in the Universe, yet there…
Exoplanet habitability is traditionally assessed by comparing a planet's semi-major axis to the location of its host star's "habitable zone," the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler…
Recent detections of carbon-bearing molecules in the atmosphere of a candidate Hycean world, K2-18 b, with JWST are opening the prospects for characterising potential biospheres on temperate exoplanets. Hycean worlds are a recently…
Thousands of planets beyond our solar system have been discovered to date, dozens of which are rocky in composition and are orbiting within the circumstellar habitable zone of their host star. The next frontier in life detection beyond our…
Dozens of habitable zone, approximately earth-sized exoplanets are known today. An emerging frontier of exoplanet studies is identifying which of these habitable zone, small planets are actually habitable (have all necessary conditions for…
The quest for atmospheric spectral signatures that may witness biological activity in exoplanets is focused on rocky planets. The best targets for future, challenging spectroscopic observations will be selected among potentially habitable…
Within the next few years, the first Earth-mass planets will be discovered around other stars. Some of those worlds will certainly lie within the classical "habitable zone" of their parent stars, and we will quickly move from knowing of no…
Earth is the only planet known to harbor life and, as a result, the search for habitable and inhabited planets beyond the Solar System commonly focuses on analogs to our planet. However, Earth's atmosphere and surface environment have…
The discovery of thousands of exoplanets and the emergence of telescopes capable of exoplanet atmospheric characterization have intensified the search for habitable worlds. Due to selection biases, many exoplanets under study are planets…
In this paper we discuss how we can read a planets spectrum to assess its habitability and search for the signatures of a biosphere. After a decade rich in giant exoplanet detections, observation techniques have now reached the ability to…
Exoplanets number in their thousands, and the number is ever increasing with the advent of new surveys and improved instrumentation. One of the most surprising things we have learnt from these discoveries is not that small-rocky planets in…
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…
Earth is the only known inhabited planet in the universe to date. However, advancements in the fields of astrobiology and observational astronomy, and the discovery of large varieties of extremophiles with extraordinary capablities to…
Rocky planets are common around other stars, but their atmospheric properties remain largely unconstrained. Thanks to a wealth of recent planet discoveries and upcoming advances in observing capability, we are poised to characterize the…
The future biosphere on Earth (as with its past) will be made up predominantly of unicellular microorganisms. Unicellular life was probably present for at least 2.5 Gyr before multicellular life appeared and will likely be the only form of…
It is currently unknown how common life is on exoplanets, or how long planets can remain viable for life. To date, we have a superficial notion of habitability, a necessary first step, but so far lacking an understanding of the detailed…