Related papers: A Methane Extension to the Classical Habitable Zon…
Habitability is usually defined as the requirement for a terrestrial planet's atmosphere to sustain liquid water. This definition can be complemented by the dynamical requirement that other planets in the system do not gravitationally…
Hydrogen in rocky planet atmospheres has been invoked in arguments for extending the habitable zone via N2-H2 and CO2-H2 greenhouse warming, and providing atmospheric conditions suitable for efficient production of prebiotic molecules. On…
Understanding the climate dynamics at the inner edge of the habitable zone (HZ) is crucial for predicting the habitability of rocky exoplanets. Previous studies using Global Climate Models (GCMs) have indicated that planets receiving high…
In the past decade, observations from space and ground have found H$_2$O to be the most abundant molecular species, after hydrogen, in the atmospheres of hot, gaseous, extrasolar planets. Being the main molecular carrier of oxygen, H$_2$O…
We study the origin and escape of catastrophically outgassed volatiles (H$_2$O, CO$_2$) from exomoons with Earth-like densities and masses of $0.1M_{\oplus}$, $0.5M_{\oplus}$ and $1M_{\oplus}$ orbiting an extra-solar gas giant inside the…
In recent years, several potentially habitable, probably terrestrial exoplanets and exoplanet candidates have been discovered. The amount of CO2 in their atmosphere is of great importance for surface conditions and habitability. In the…
The methylidyne radical CH is commonly used as a proxy for H$_2$ in the cold, neutral phase of the interstellar medium. The optical spectroscopy of CH is limited by interstellar extinction, whereas far-infrared observations provide an…
Understanding when global glaciations occur on Earth-like planets is a major challenge in climate evolution research. Most models of how greenhouse gases like CO2 evolve with time on terrestrial planets are deterministic, but the complex,…
Terrestrial planets in the Habitable Zone of Sun-like stars are priority targets for detection and observation by the next generation of space telescopes. Earth's long-term habitability may have been tied to the geological carbon cycle, a…
Over 4 billion years ago, Earth is thought to have been a hazy world akin to Saturn's moon Titan. The organic hazes in the atmosphere at this time could contain a vast inventory of life's building blocks, and thus may have seeded warm…
Atmospheric ozone plays an important role on the temperature structure of the atmosphere. However, it has not been included in previous studies on the effect of an increasing solar radiation on the Earth's climate. Here we study the climate…
The Kepler space telescope has detected transits of objects as small as the Earth's Moon, and moons as small as 0.2 Earth masses can be detected in the Kepler data by transit timing and transit duration variations of their host planets.…
Water-rich planets such as Earth are expected to become eventually uninhabitable, because liquid water does not remain stable at the surface as surface temperatures increase with the solar luminosity over time. Whether a large increase of…
We investigate a new class of habitable planets composed of water-rich interiors with massive oceans underlying H2-rich atmospheres, referred to here as Hycean worlds. With densities between those of rocky super-Earths and more extended…
Exoplanets that receive stellar irradiance of approximately Earth's or less have been discovered and many are suitable for spectral characterization. Here we focus on the temperate planets that have massive H2-dominated atmospheres, and…
A large number of studies have responded to the growing body of confirmed terrestrial habitable zone exoplanets by presenting models of various possible climates. However, the impact of the partial pressure of background gases such as N$_2$…
Pluto possesses a thin atmosphere primarily composed of N2, with minor constituents including CO and CH4. Photochemical processes generate distinct haze layers as observed by the New Horizons spacecraft. However, the mechanisms governing…
Increases in atmospheric CO2 and CH4 result from a combination of forcing from anthropogenic emissions and Earth System feedbacks that reduce or amplify the effects of those emissions on atmospheric concentrations. Despite decades of…
Stellar activity and planetary atmospheric properties have the potential to strongly influence habitability. To date, neither have been adequately studied in the multiverse context, so there has been no assessment of how these effects…
Among the most highly valued of exoplanetary discoveries are those of terrestrial planets found to reside within the Habitable Zone (HZ) of the host star. In particular, those HZ planets with relatively bright host stars will serve as…