Related papers: Photosynthesis on Exoplanets and Exomoons from Ref…
One of the great quests of astronomy is to obtain the spectrum of a terrestrial planet orbiting within the habitable zone of its star, and the dominant challenge in doing so is to isolate the light of the planet from that of the star.…
The diversity and quantity of moons in the Solar System suggest a manifold population of natural satellites exist around extrasolar planets. Of peculiar interest from an astrobiological perspective, the number of sizable moons in the…
Photochemistry has the potential to substantially impact the atmospheric composition of exoplanets with consequences on the radiative transfer, thermal structure and dynamics of the atmospheres, particularly in UV-rich stellar environments.…
Standard definitions of habitability assume that life requires the presence of planetary gravity wells to stabilize liquid water and regulate surface temperature. Here the consequences of relaxing this assumption are evaluated. Temperature,…
Using the Socrates photolysis scheme, we present newly calculated photolysis rates under modern Earth atmospheric conditions for species directly relevant to Earth and species relevant to different atmospheric compositions. We compare to a…
As photosynthesis on Earth produces the primary signatures of life that can be detected astronomically at the global scale, a strong focus of the search for extrasolar life will be photosynthesis, particularly photosynthesis that has…
We perform a quantitative assessment for the potential for photosynthesis in hydrothermal vents in the deep ocean. The photosynthetically active radiation in this case is from geothermal origin: the infrared thermal radiation emitted by hot…
Future direct-imaging exoplanet missions such as WFIRST/AFTA, Exo-C, and Exo-S will measure the reflectivity of exoplanets at visible wavelengths. The exoplanets to be observed will be located further away from their parent stars than is…
Exoplanet discoveries have motivated numerous efforts to find unseen populations of exomoons, yet they have been unsuccessful. A plausible explanation is that most discovered planets are located on close-in orbits, which would make their…
Context: Detecting moons around exoplanets is a major goal of current and future observatories. Moons are suspected to influence rocky exoplanet habitability, and gaseous exoplanets in stellar habitable zones could harbour abundant and…
More than 200 moons exist in our Solar System, yet no exomoon has been confirmed to date. While the innermost two planets of the Solar System lack natural satellites and most studies favour the existence of exomoons around long-period…
Exomoons around free-floating planets (FFPs) can survive their host planet's ejection. Such ejections can increase their orbital eccentricity, providing significant tidal heating in the absence of any stellar energy source. Previous studies…
M dwarfs host most of the exoplanets in the local Milky Way. Some of these planets, ranging from sub-Earths to super-Jupiters, orbit in their stars' habitable zones (HZs), although many likely possess surface environments that preclude…
On planets near M dwarfs, photosynthesis (PS) will occur with an effectiveness which depends on the supply of visible photons with wavelengths between 400 and 700 nm. In this paper, we quantify the effectiveness of PS in two contexts which…
Assuming our Solar System as typical, exomoons may outnumber exoplanets. If their habitability fraction is similar, they would thus constitute the largest portion of habitable real estate in the Universe. Icy moons in our Solar System, such…
We demonstrate the ability of existing and planned telescopes, on the ground and in space, to directly image tidally heated exomoons orbiting gas-giant exoplanets. Tidally heated exomoons can plausibly be far more luminous than their host…
Understanding a planet's atmosphere is a necessary condition for understanding not only the planet itself, but also its formation, structure, evolution, and habitability, This puts a premium on obtaining spectra, and developing credible…
Planned astronomical observatories of the 2020s will be capable of obtaining reflected light photometry and spectroscopy of cool extrasolar giant planets. Here we explain that such data are valuable both for understanding the origin and…
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…
Terrestrial exoplanets in habitable zones are ubiquitous. It is, however, unknown which have Earth-like or Venus-like climates. Distinguishing different planet-types is crucial for determining whether a planet could be habitable. We…