Earth’s volatile elements (H, C, and N) are essential to maintaining habitable conditions for metazoans and simpler life forms. However, identifying the sources (comets, meteorites, and trapped nebular gas) that […]
astro-ph.EP]
Posted inExoplanets, -moons, -comets, Habitable Zones
Remote Life Detection Criteria, Habitable Zone Boundaries, and the Frequency of Earthlike Planets around M and Late-K Stars
The habitable zone (HZ) around a star is typically defined as the region where a rocky planet can maintain liquid water on its surface. That definition is appropriate, because this […]
Posted inAstrochemistry, Exoplanets, -moons, -comets, Origin & Evolution of Life
Influence of Galactic Cosmic Rays on Ion-Neutral Hydrocarbon Chemistry in Upper Atmospheres of Free-Floating Exoplanets
Cosmic rays may be linked to the formation of volatiles necessary for prebiotic chemistry. We explore the effect of cosmic rays in a hydrogen-dominated atmosphere, as a proof-of-concept that ion-neutral […]
Posted inAstrochemistry, Exoplanets, -moons, -comets, Habitable Zones
Feasibility Studies for the Detection of O2 in an Earth-like Exoplanet
We present the results of simulations on the detectability of O2 in the atmosphere of Earth twins around nearby low mass stars using high resolution transmission spectroscopy. We explore such […]
Posted inAstrochemistry, Exoplanets, -moons, -comets
A Search for Methane in the Atmosphere of GJ 1214b via GTC Narrow-Band Transmission Spectrophotometry
We present narrow-band photometric measurements of the exoplanet GJ 1214b using the 10.4 m Gran Telescopio Canarias (GTC) and the OSIRIS instrument. Using tuneable filters we observed a total of […]
Posted inExoplanets, -moons, -comets
The Mass-Radius Relation Between 60 Exoplanets Smaller than 4 Earth Radii
We study the masses and radii of 60 exoplanets smaller than 4 Earth radii with orbital periods shorter than 100 days. We find a nearly linear mass-radius relation: M/M_E= 3.17 […]
Posted inAstrochemistry, Astronomy & Telescopes, Beta Pictoris
Herschel HIFI observations of ionised carbon in the Pictoris debris disk
Context: The dusty debris disk around the ~20 Myr old main-sequence A-star beta Pic is known to contain gas. Evidence points towards a secondary origin of the gas as opposed […]
Posted inExtremeophiles and Extreme Environments, Habitable Zones, Microbiology & Virology
Refuges for Life and Novel Microbial Biospheres on Terrestrial Planets Near the End of Their Habitable Lifetimes
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 […]
Posted inExoplanets, -moons, -comets, Extremeophiles and Extreme Environments, Habitable Zones
Final Signs of Life on Terrestrial Planets Near the End of Their Habitable Lifetimes
The biosignatures of life on Earth do not remain static, but change considerably over the planet’s habitable lifetime. Earth’s future biosphere, much like that of the early Earth, will consist […]
Posted inAstrochemistry, Exoplanets, -moons, -comets
Electrostatic Activation of Prebiotic Chemistry in Substellar Atmospheres
Charged dust grains in the atmospheres of exoplanets may play a key role in the formation of prebiotic molecules, necessary to the origin of life. Dust grains submerged in an […]