habitability Archives - Page 58 of 98 - Astrobiology

Depiction of all 18 systems that spend at least part of their time within their respective HZs. Empty markers in panel (c) represent actual planetary mass values as opposed to minimum mass values, which are represented by filled in markers. -- The Astrophysical Journal

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Press Release, Stellar Cartography

The Habitability Of F-Type Star Systems

by Keith CowingSeptember 20, 2024September 20, 2024

Physicists at The University of Texas at Arlington have published a study of F-type star systems, in which they explored systems where the planets spend at least part of their […]

Comparison of the TRAPPIST-1 system to our inner solar system -- NASA (larger image)

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, TRAPPIST-1

Drifts Of The Sub-stellar Points Of The TRAPPIST-1 Planets

by Keith CowingSeptember 19, 2024September 19, 2024

Accurate modeling of tidal interactions is crucial for interpreting recent JWST observations of the thermal emissions of TRAPPIST-1~b and c and for characterizing the surface conditions and potential habitability of […]

The skies above the Amazon are almost always churning with clouds and storms, making the basin one of the most difficult places for scientists to map and monitor. The astronaut photograph above—taken while the International Space Station was over the Brazilian state of Tocantins—captures a common scene from the wet season. Vast pillars of moisture rise via convection and then spread outward into anvil clouds as they collide with the stratosphere. larger image -- NASA

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Habitable Zones, Status Report, Water/Hycean Worlds & Oceanography

Substantial Extension of the Lifetime of the Terrestrial Biosphere

by Keith CowingSeptember 18, 2024September 18, 2024

Approximately one billion years (Gyr) in the future, as the Sun brightens, Earth’s carbonate-silicate cycle is expected to drive CO2 below the minimum level required by vascular land plants, eliminating […]

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Status Report

Self-oxidation of the Atmospheres of Rocky Planets with Implications for the Origin of Life

by Keith CowingSeptember 18, 2024September 18, 2024

Rocky planets may acquire a primordial atmosphere by outgassing of volatiles from their magma ocean. The distribution of O between H2O, CO and CO2 in chemical equilibrium subsequently changes significantly […]

Zonally and temporally averaged snow fraction for our reference non-impacted model (top left) and at three points in time post-impact for our combined water and heat deposition impact model: 6 months post-impact (top right), 1 year post-impact (bottom left), and 15 years post-impact (bottom right), by which time the impacted models snow fraction has returned to a state clost to that found in our non-impacted reference state. -- astro-ph.EP

Atmospheres, Climate, Weather, Comets and Asteroids, Exoplanets, -moons, -comets, Extinction events, Icy Worlds, Impact events

The Impact of Icy Cometary ‘Impacts’ on Exoplanetary Atmospheres I: Tidally-Locked Terrestrial Exoplanets

by Keith CowingSeptember 18, 2024

Impacts by rocky and icy bodies are thought to have played a key role in shaping the composition of solar system objects, including the Earth’s habitability. Hence, it is likely […]

Hadean Earth - credit: Alec Brenner via Harvard University

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Habitable Zones, Microbiology & Virology, Status Report, Water/Hycean Worlds & Oceanography

New Estimates of Nitrogen Fixation on Early Earth

by Keith CowingSeptember 17, 2024September 17, 2024

Fixed nitrogen species generated by the early Earth’s atmosphere are thought to be critical to the emergence of life and the sustenance of early metabolisms.

The condensation sequence for a solar composition atmosphere where dashed lines indicate the condensation curves for a variety of typically assumed condensable species. The model planet atmosphere day (red) and night (blue) temperature profiles are shown. In the case of a primordial solar composition atmosphere there may exist a favorable region of temperature phase space where we do not expect significant opacity from condensational clouds (at ∼ 400 - 800 K). However, given the presumed diversity of terrestrial atmospheres, such a favorable region may be unlikely to exist. -- astro-ph.EP

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Status Report, TRAPPIST-1

Nightside Clouds on Tidally-locked Terrestrial Planets Mimic Atmosphere-Free Scenarios

by Keith CowingSeptember 13, 2024September 13, 2024

We investigate the impact of nightside cloud formation on the observable night-day contrast of tidally-locked terrestrial planet atmospheres.

Model framework for describing Xe-loss and fractionation from the martian atmosphere. Impacts eject all material in a central cone, with an annulus of partially ionized material escaping the atmosphere according to whether ions survive to high altitude to connect with Mars’s open magnetic field lines (42). -- astro-ph.EP

Atmospheres, Climate, Weather, Habitable Zones, Impact events, Mars, Status Report

Impact Sculpting Of The Early Martian Atmosphere

by Keith CowingSeptember 13, 2024September 13, 2024

Intense bombardment of solar system planets in the immediate aftermath of protoplanetary disk dissipation has played a key role in their atmospheric evolution.

“Hyper-realistic” RGB images of Control at a phase of 40°, generated with PSG GlobES. Clockwise starting from the top left: (a) true color image, without BVLO. Proxima b appears orange because Proxima Centauri is a cool star which emits mostly red light in the visible. In this image, the darkest regions on the planet are oceans, and the lighter regions are ice or clouds. To identify clouds, compare with b. (b) the cloud cover fraction, with high numbers indicating grid cells mostly covered with clouds. (c) false color image of Control with BVLO. The BVLO appear purple because of Qy feature strongly absorbs in the green channel at 1um. (d) same as a, but with BVLO added (Amax = 1). The BVLO fill in the open water regions. To easily see regions of BVLO coverage, compare with purple regions in c. -- astro-ph.EP

Analog Studies, Astrochemistry, Astrogeology, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Proxima Centauri, Status Report

Detectability Simulations of a NIR Surface Biosignature on Proxima Centauri b with Future Space Observatories

by Keith CowingSeptember 11, 2024September 11, 2024

Telescope missions are currently being designed which will make direct imaging of habitable exoplanets possible in the near future, and studies are needed to quantify the detectability of biosignature features […]

Magnetic field analysis for the star 2M07590587+1523294. The left panels show the four Fe I lines used in the modeling: black dots are the observed APOGEE spectrum, red dashed lines are synthetic profiles computed without a magnetic field, and dark blue lines are our best fits obtained from the MCMC modeling. The right panel is a corner plot that presents the median and uncertainties (from 16th and 84th percentiles) of the derived parameters, which includes filling factors from magnetic fields between 2 and 6 kG in steps of 2 kG. We also show the final magnetic field result and its uncertainties. -- astro-ph.SR

Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Magnetic Fields, Electromagnetism, bioelectricity,, Radiation, Space Weather & Heliophysics, Status Report

Magnetic Fields in a Sample of Planet-hosting M Dwarf Stars from Kepler, K2, and TESS Observed by APOGEE

by Keith CowingSeptember 11, 2024September 11, 2024

Stellar magnetic fields have a major impact on space weather around exoplanets orbiting low-mass stars. From an analysis of Zeeman-broadened Fe I lines measured in near-infrared SDSS/APOGEE spectra, mean magnetic […]