atmosphere Archives

The pebble surface density for scenario 1 (top) and scenario 2 (bottom) is depicted for different α-viscosities, dependent on disk radius and time. In each case, the red vertical line denotes the water-ice line, and the green line marks the position of the gas giant, if present. In the scenario with a gas giant, the accumulation of blocked pebbles exterior to the gas giant’s position is visible. Further accumulations within the water-ice line result from the recondensation of outwardly diffusing gas at different evaporation lines. -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Constraining The Formation History Of The HAT-P-11 System By Atmospheric Abundances

by Keith CowingOctober 23, 2023October 20, 2023

The chemical fingerprint of a planet reveals information about its formation history regarding when and where it formed. The water content of a planet can help to constrain its formation […]

Comparison of measured and simulated absorbances of C2H6 (top) and C2H2 (bottom) for a spectral resolution of 0.45 cm-1 in the case of the H2:CH4:N2 gas mixture after 24 hr of irradiation at 473 K. The simulated spectra were obtained following the procedure described in Section 2.2. -- astro-ph.EP

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Experimental Investigation of the Photochemical Production of Hydrocarbons in Warm Gas Giant Exoplanet Atmospheres

by Keith CowingOctober 19, 2023October 19, 2023

In warm (equilibrium temperature <1000 K) gas giant exoplanet atmospheres, the observation of trace species in abundances deviating from thermochemical equilibrium predictions could be used as an indicator of disequilibrium […]

Transmission spectra of GJ 1132 b from all three data reduction pipelines and both visits. Upper panel: the Eureka! (yellow), FIREFLy (pink), and ExoTiC-JEDI (blue) reductions are shown for both visits at R∼100. Also shown are the differences between reductions (solid, dashed, and dotted gray lines) in units of σ, demonstrating the agreement between pipelines within a single visit. A ±1σ shaded region is overlaid. Bottom panel: the Eureka! reduction for both visits, with the NIRSpec detector gap denoted by the shaded gray region. The shaded yellow regions show two important wavelength ranges that differ the most between the visits (see Sections 4.1 and 4.4.1 for further discussion on these differences). -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Double Trouble: Two Transits of the Super-Earth GJ 1132 b Observed with JWST NIRSpec G395H

by Keith CowingOctober 19, 2023October 19, 2023

The search for rocky planet atmospheres with JWST has focused on planets transiting M dwarfs. Such planets have favorable planet-to-star size ratios, enhancing the amplitude of atmospheric features. Since the […]

Retrieved spectral feature amplitude, AH, compared to clear, cloudy, and hazy atmosphere models from Morley et al. (2015). For the clear and cloudy models, the dotted lines indicate a 100× Solar metallicity atmosphere, and the dot-dashed lines a 300× Solar atmosphere. All hazy models were calculated at 50× Solar metallicity, the dotted lines are 1% haze precursor conversion, and the dashed lines are 10%. The green open markers, shown for context, are the measured CH4-retrieved AH values for K2-18 b and TOI-270 d. The black open markers, shown for context, are the Kepler-51 planets, which are excluded from the trend analysis due to their exceptionally low densities, and GJ 1214 b, which was found to significantly bias the trend fit due to the extremely precise flatness of its spectrum. -- astro-ph.EP

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Status Report

Clouds and Clarity: Revisiting Atmospheric Feature Trends in Neptune-size Exoplanets

by Keith CowingOctober 13, 2023October 13, 2023

Over the last decade, precise exoplanet transmission spectroscopy has revealed the atmospheres of dozens of exoplanets, driven largely by observatories like the Hubble Space Telescope.

Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Status Report

An Extensively Validated C/H/O/N Chemical Network For Hot Exoplanet Disequilibrium Chemistry

by Keith CowingOctober 13, 2023October 13, 2023

We aimed to build a new and updated C0-C2 chemical network to study the CHON disequilibrium chemistry of warm and hot exoplanet atmospheres that relies on extensively validated and recent […]

AI - Data - Apps - Cybernetics, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Status Report

Modelling Non-Condensing Compositional Convection for Applications to Super-Earth and Sub-Neptune Atmospheres

by Keith CowingOctober 13, 2023October 13, 2023

Compositional convection is atmospheric mixing driven by density variations caused by compositional gradients. Previous studies have suggested that compositional gradients of atmospheric trace species within planetary atmospheres can impact convection […]

Particle number density in cm−3 (left) and particle radius in µm (right) from Atmos, for each of the haze profiles. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Status Report

3D Simulations Of The Archean Earth Including Photochemical Haze Profiles

by Keith CowingOctober 11, 2023October 11, 2023

We present results from 3D simulations of the Archean Earth including a prescribed (non-interactive) spherical haze generated through a 1D photochemical model.

Bayesian analysis of the posterior likelihood of life, P(life|observation), based on assuming an observed value for network metrics and methane gas abundance. Given that the probability for life to exist on an exoplanet is unknown, we assess the posterior likelihood over a range of prior probabilities for life, P(life). Grey Regions highlight metric values that are associated with a zero probability of life and are therefore anti-biosignatures for the sets of models compared herein. In general, network metrics can provide greater constraints on the probability of life given a set of observations than CH4 abundance alone, allowing distinguishing cases where Earth-like methanogenesis can be ruled out even when CH4 abundance alone is not conclusive. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, SETI & Technosignatures, Status Report

A Complex Systems Approach to Exoplanet Atmospheric Chemistry: New Prospects for Ruling Out the Possibility of Alien Life-As-We-Know-It

by Keith CowingOctober 10, 2023October 10, 2023

The near-term capability to characterize terrestrial exoplanet atmospheres may bring us closer to discovering alien life through atmospheric data.

Detection of the runaway greenhouse threshold. From simulated radius and instellation measurements of a large (N = 500) survey, we compute the moving average (blue confidence intervals) and fit the runaway greenhouse hypothesis to it (Eqn. 4, random draws from the posterior in red). The pattern is detected with high significance. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Extinction events, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Status Report

Bioverse: The Habitable Zone Inner Edge Discontinuity as an Imprint of Runaway Greenhouse Climates on Exoplanet Demographics

by Keith CowingOctober 10, 2023October 9, 2023

Long-term magma ocean phases on rocky exoplanets orbiting closer to their star than the runaway greenhouse threshold – the inner edge of the classical habitable zone – may offer insights […]

Transmission spectrum of HD 209458b, observed with HST STIS (orange points), HST WFC3 (red points), and Spitzer (green points). Overplotted are median model spectra drawn from the posteriors of each of the six retrievals described in Section 3.2. All models are the same except for their treatment of clouds and hazes. Median forward models have been downsampled to a resolution R = 200 for clarity. PL+G refers to power-law haze + grey cloud models, and A&M refers to Ackerman & Marley cloud models. -- astro-ph.IM

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Methods For Incorporating Model Uncertainty Into Exoplanet Atmospheric Analysis

by Keith CowingOctober 7, 2023October 7, 2023

A key goal of exoplanet spectroscopy is to measure atmospheric properties, such as abundances of chemical species, in order to connect them to our understanding of atmospheric physics and planet […]

atmosphere

Constraining The Formation History Of The HAT-P-11 System By Atmospheric Abundances

Experimental Investigation of the Photochemical Production of Hydrocarbons in Warm Gas Giant Exoplanet Atmospheres

Double Trouble: Two Transits of the Super-Earth GJ 1132 b Observed with JWST NIRSpec G395H

Clouds and Clarity: Revisiting Atmospheric Feature Trends in Neptune-size Exoplanets

An Extensively Validated C/H/O/N Chemical Network For Hot Exoplanet Disequilibrium Chemistry

Modelling Non-Condensing Compositional Convection for Applications to Super-Earth and Sub-Neptune Atmospheres

3D Simulations Of The Archean Earth Including Photochemical Haze Profiles

A Complex Systems Approach to Exoplanet Atmospheric Chemistry: New Prospects for Ruling Out the Possibility of Alien Life-As-We-Know-It

Bioverse: The Habitable Zone Inner Edge Discontinuity as an Imprint of Runaway Greenhouse Climates on Exoplanet Demographics

Methods For Incorporating Model Uncertainty Into Exoplanet Atmospheric Analysis

On The Foundations Of Anthropic Reasoning: Implications For Life Across The Universe

NASA Curation Community Conversation Webinar

The Atmospheric Chemistry and Surface Interactions on Mars (ACSIOM) Workshop 2025

An ALMA View On Molecular Complexity: Water, Methanol, And Methyl Formate In The HD 100546 And IRS 48 Disks

The Occurrence of Circumbinary Planets Around TESS M-dwarf Eclipsing Binaries