Results 91 to 100 of about 193,103 (196)
Solar Wind Power Likely Governs Uranus' Thermosphere Temperature
Geophysical Research Letters, Volume 51, Issue 22, 28 November 2024.Abstract Observations of Uranus in the near‐infrared by ground‐based telescopes from 1992 to 2018 have shown that the planet's upper atmosphere (thermosphere) steadily cooled from ∼700 to ∼450 K. We explain this cooling as due to the concurrent decline in the power of the solar wind incident on Uranus' magnetic field, which has dropped by ∼50% over the
A. Masters +3 more
wiley +1 more source
arXiv, 2017 Earth's atmosphere has evolved as volatile species cycle between the atmosphere, ocean, biomass and the solid Earth. The geochemical, biological and astrophysical processes that control atmospheric evolution are reviewed from an "Earth Systems" perspective, with a view not only to understanding the history of Earth, but also to generalizing to other ...
arxiv
Blowin’ in the Nonisothermal Wind: Core-powered Mass Loss with Hydrodynamic Radiative Transfer
The Astrophysical JournalThe mass loss rates of planets undergoing core-powered escape are usually modeled using an isothermal Parker-type wind at the equilibrium temperature, T _eq .
William Misener +3 more
doaj +1 more source
The Astrophysical JournalExoplanets with short orbit periods reside very close to their host stars. They transition very rapidly between different sectors of the circumstellar space environment along their orbit, leading to large variations of the magnetic field in the vicinity ...
Ofer Cohen +6 more
doaj +1 more source
An Oxidation Gradient Straddling the Small Planet Radius Valley
The Astrophysical JournalWe present a population-level view of volatile gas species (H _2 , He, H _2 O, O _2 , CO, CO _2 , CH _4 ) distribution during the sub-Neptune to rocky planet transition, revealing in detail the dynamic nature of small planet atmospheric compositions. Our
Collin Cherubim +5 more
doaj +1 more source
A Large and Variable Leading Tail of Helium in a Hot Saturn Undergoing Runaway Inflation
The Astronomical JournalAtmospheric escape shapes the fate of exoplanets, with statistical evidence for transformative mass loss imprinted across the mass–radius–insolation distribution.
Michael Gully-Santiago +16 more
doaj +1 more source
Atmospheric escape from exoplanets: recent observations and theoretical models [PDF]
arXivThe review aims to give an overview of atmospheric escape processes from exoplanets. I briefly discuss the physics of various escape processes responsible for atmospheric escape across different types of exoplanets. Transmission spectroscopy is one of the major workhorses to observe the escaping atmosphere from exoplanets. I discuss recent observations
arxiv
The Astrophysical JournalTerrestrial planets currently in the habitable zone around M dwarfs are estimated to have been in runaway greenhouse conditions for up to ∼1 Gyr due to the long-term pre-main-sequence phase of M dwarfs.
Yo Kawamura +7 more
doaj +1 more source
Characterizing the Atmospheres of Irradiated Exoplanets at High Spectral Resolution [PDF]
arXiv, 2019 The best-characterized exoplanets to date are planets on close-in transiting orbits around their host stars. The high level of irradiation and transiting geometry of these objects make them ideal targets for atmospheric investigations. However, the modest apertures of many current telescopes allow mostly low resolution spectra to be observed for ...
arxiv
Scientific Return of Coronagraphic Exoplanet Imaging and Spectroscopy Using WFIRST [PDF]
arXiv, 2014 In this study, we explore and review the scientific potential for exoplanet characterization by a high-contrast optical coronagraph on WFIRST/AFTA. We suggest that the heterogeneity in albedo spectra and planet/star flux ratios as a function of orbital distance, planet mass, and composition expected for the giant exoplanets at separations from their ...
arxiv