Several clues indicate that Titan’s atmosphere has been depleted in methane during some period of its history, possibly as recently as 0.5-1 billion years ago. It could also happen in […]
astro-ph.EP]
Posted inExoplanets, -moons, -comets
A Stellar-mass-dependent Drop in Planet Occurrence Rates
The Kepler Space Telescope has discovered a large number of planets up to one year periods and down to terrestrial sizes. The cool star subsample allows characterization of small planets […]
Posted inExoplanets, -moons, -comets, Habitable Zones
GJ 832c: A Super-Earth in the Habitable Zone
We report the detection of GJ 832c, a super-Earth orbiting near the inner edge of the habitable zone of GJ 832, an M dwarf previously known to host a Jupiter […]
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets
Transit and Radial Velocity Survey Efficiency Comparison for a Habitable Zone Earth
Transit and radial velocity searches are two techniques for identifying nearby extrasolar planets to Earth that transit bright stars. Identifying a robust sample of these exoplanets around bright stars for […]
Posted inAstrochemistry, Exoplanets, -moons, -comets, Habitable Zones
Chemical Modeling of Exoplanet Atmospheres
The past twenty years have revealed the diversity of planets that exist in the Universe. It turned out that most of exoplanets are different from the planets of our Solar […]
Posted inBiosignatures & Paleobiology, Exoplanets, -moons, -comets
Detecting Industrial Pollution in the Atmospheres of Earth-like Exoplanets
Detecting biomarkers, such as molecular oxygen, in the atmospheres of transiting exoplanets has been a major focus in the search for alien life. We point out that in addition to […]
Posted inExoplanets, -moons, -comets
Exoplanet Population Inference and the Abundance of Earth Analogs from Noisy, Incomplete Catalogs
No true extrasolar Earth analog is known. Hundreds of planets have been found around Sun-like stars that are either Earth-sized but on shorter periods, or else on year-long orbits but […]
Posted inAstrochemistry
Characterization and Remote Sensing of Biological Particles Using Circular Polarization
Biological molecules are characterized by an intrinsic asymmetry known as homochirality. The result is optical activity of biological materials and circular polarization in the light scattered by microorganisms, cells of […]
Posted inExoplanets, -moons, -comets
Titan Solar Occultation Observations Reveal Transit Spectra of a Hazy World
High altitude clouds and hazes are integral to understanding exoplanet observations, and are proposed to explain observed featureless transit spectra. However, it is difficult to make inferences from these data […]
Posted inImpact events
Exploring the Role of the Sun's Motion in Terrestrial Comet Impacts
The cratering record on the Earth and Moon shows that our planet has been exposed to high velocity impacts for much or all of its existence. Some of these craters […]