Related papers: Inner Edge of Habitable Zones for Earth-sized Plan…
How do habitable environments arise and evolve within the context of their planetary systems? This is one fundamental question, and it can be addressed partly by identifying how planets in habitable zones obtain water. Historically,…
Arid terrestrial exoplanets are potentially abundant and are thus interesting targets in the search for life. In particular, M-dwarf planets such as those in the TRAPPIST-1 system may possess limited surface water, whereas early solar…
Understanding the limits of rocky planet habitability is one of the key goals of current and future exoplanet characterization efforts. An intrinsic concept of rocky planet habitability is the Habitable Zone. To date, the most widely used…
Many extrasolar (bound) terrestrial planets and free-floating (unbound) planets have been discovered. The existence of bound and unbound terrestrial planets with liquid water is an important question, and of particular importance is the…
A balanced ratio of ocean to land is believed to be essential for an Earth-like biosphere and one may conjecture that plate-tectonics planets should be similar in geological properties. After all, the volume of continental crust evolves…
Conventionally, a habitable planet is one that can support liquid water on its surface. Habitability depends on temperature, which is set by insolation and the greenhouse effect, due mainly to CO2 and water vapor. The CO2 level is increased…
The circumstellar liquid-water habitable zone guides our search for potentially inhabited exoplanets, but remains observationally untested. We show that the inner edge of the habitable zone can now be mapped among exoplanets using their…
The habitable zone (HZ) describes the range of orbital distances around a star where the existence of liquid water on the surface of an Earth-like planet is in principle possible. While 3D climate studies can calculate the water vapor, ice…
During the post-main sequence phase of stellar evolution the orbital distance of the habitable zone, which allows for liquid surface water on terrestrial planets, moves out past the system's original frost line, providing an opportunity for…
Water photolysis and hydrogen loss from the upper atmospheres of terrestrial planets is of fundamental importance to climate evolution but remains poorly understood in general. Here we present a range of calculations we performed to study…
Terrestrial-type exoplanets orbiting nearby red dwarf stars (M-dwarfs) are among the best targets for atmospheric characterization and biosignature searches in the near future. Recent evolutionary studies have suggested that terrestrial…
As the characterization of exoplanet atmospheres proceeds, providing insights into atmospheric chemistry and composition, a key question is how much deeper into the planet we might be able to see from its atmospheric properties alone. For…
Understanding the set of conditions that allow rocky planets to have liquid water on their surface -- in the form of lakes, seas or oceans -- is a major scientific step to determine the fraction of planets potentially suitable for the…
The habitable zones of main sequence stars have traditionally been defined as the range of orbits that intercept the appropriate amount of stellar flux to permit surface water on a planet. Terrestrial exoplanets discovered to orbit M stars…
Low-gravity waterworlds ($M\lesssim 0.1 M_{\oplus}$) are of interest for their potential habitability. The weakly bound atmospheres of such worlds have proportionally larger radiative surfaces and are more susceptible to escape. We conduct…
Terrestrial planets covered globally with thick oceans (termed ocean planets) in the habitable zone were previously inferred to have extremely hot climates in most cases. This is because ${\rm H_2O}$ high-pressure (HP) ice on the seafloor…
The planets of the Solar System divide neatly between those with atmospheres and those without when arranged by insolation ($I$) and escape velocity ($v_{\mathrm{esc}}$). The dividing line goes as $I \propto v_{\mathrm{esc}}^4$. Exoplanets…
Planets with masses between Earth and Neptune often have radii that imply the presence of volatiles, suggesting that water may be abundant in their interiors. However, directly observing the precise water mass fraction and water…
Super-Earths are highly irradiated, small planets with bulk densities approximately consistent with Earth. We construct combined interior-atmosphere models of super-Earths that trace the partitioning of water throughout a planet, including…
Among potentially habitable worlds, rocky planets orbiting M dwarfs offer the most favorable prospects for atmospheric characterization, yet their climates may differ substantially from those of Earth analogs. In the tidally locked limit,…