Related papers: Atmospheric nitrogen evolution on Earth and Venus
One of the key goals of exoplanet science is the atmospheric characterisation of super-Earths. Atmospheric abundances provide insight on the formation and evolution of those planets and help to put our own rocky planets in context.…
Earth's water, intrinsic oxidation state, and metal core density are fundamental chemical features of our planet. Studies of exoplanets provide a useful context for elucidating the source of these chemical traits. Planet formation and…
The Martian isotopic record displays a dichotomy in volatile compositions. Interior volatiles from the mantle record a chondritic heritage (e.g., H, N, Kr, Xe) whereas the atmospheric reservoir of Kr and Xe - which do not currently…
Bioavailable nitrogen is thought to be a requirement for the origin and sustenance of life. Before the onset of biological nitrogen fixation, abiotic pathways to fix atmospheric N2 must have been prominent to provide bioavailable nitrogen…
Xenon, which is quite inert under ambient conditions, may become reactive under pressure. The possibility of formation of stable xenon oxides and silicates in the interior of the Earth could explain the atmospheric missing xenon paradox.…
The abundance of nitrogen in the interstellar medium is a powerful probe of star for- mation processes over cosmological timescales. Since nitrogen can be produced both in massive and intermediate-mass stars with metallicity-dependent…
The atmosphere of Venus remains mysterious, with many outstanding chemical connundra. These include: the unexpected presence of ~10 ppm O2 in the cloud layers; an unknown composition of large particles in the lower cloud layers; and hard to…
We discuss how greenhouse gases affect radiation transfer in Earth's atmosphere. We explain how greenhouse gases like water vapor or carbon dioxide, differ from non-greenhouse gases like nitrogen or oxygen. Using simple thermodynamics and…
The evolution and escape of the martian atmosphere and the planet's water inventory can be separated into an early and late evolutionary epoch. The first epoch started from the planet's origin and lasted $\sim$500 Myr. Because of the high…
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…
Water cycling between Earth's mantle and surface has previously been modelled and extrapolated to rocky exoplanets, but these studies neglected the host star. M-dwarf stars are more common than Sun-like stars and at least as likely to host…
Archean atmospheric evolution is the transition from an abiological atmosphere, to an atmosphere for which the composition and therefore climate is highly altered by life. We review the key processes and transitions in this evolution.
Here we investigate how small amounts of hydrogen (much smaller than the mass of the exoplanet) above a magma ocean on a rocky exoplanet may modify the atmospheric chemistry and atmospheric escape.We use a chemical model of a magma ocean…
The origin of life on Earth involves the early appearance of an information-containing molecule such as RNA. The basic building blocks of RNA could have been delivered by carbon-rich meteorites, or produced in situ by processes beginning…
The origin of life on Earth would benefit from a prebiotic atmosphere that produced nitriles, like HCN, which enable ribonucleotide synthesis. However, geochemical evidence suggests that Hadean air was relatively oxidizing with negligible…
Atmospheres play a crucial role in planetary habitability. Around M dwarfs and young Sun-like stars, planets receiving the same insolation as the present-day Earth are exposed to intense stellar X-rays and extreme-ultraviolet (XUV)…
In the study of planetary habitability and terrestrial atmospheric evolution, the divergence of surface conditions for Venus and Earth remains an area of active research. Among the intrinsic and external influences on the Venusian climate…
Martian atmospheric neon (Ne) has been detected by Viking and also found as trapped gas in Martian meteorites, though its abundance and isotopic composition have not been well determined. Because the timescale of Ne loss via atmospheric…
The hydrogen and water molecules respond very differently to the collisional-radiative processes taking place in planetary atmospheres. Naturally, the question arises whether H2O-rich atmospheres are more (or less) resilient to long-term…
The climate of Mars likely evolved from a warmer, wetter early state to the cold, arid current state. However, no solutions for this evolution have previously been found to satisfy the observed geological features and isotopic measurements…