Predictions for Observable Atmospheres of Trappist-1 Planets from a Fully Coupled Atmosphere-Interior Evolution Model

Abstract

The Trappist-1 planets provide a unique opportunity to test the current understanding of rocky planet evolution. The James Webb Space Telescope is expected to characterize the atmospheres of these planets, potentially detecting CO${}_2$, CO, H${}_2$O, CH${}_4$, or abiotic O${}_2$ from water photodissociation and subsequent hydrogen escape. Here, we apply a coupled atmosphere-interior evolution model to the Trappist-1 planets to anticipate their modern atmospheres. This model, which has previously been validated for Earth and Venus, connects magma ocean crystallization to temperate geochemical cycling. Mantle convection, magmatic outgassing, atmospheric escape, crustal oxidation, a radiative-convective climate model, and deep volatile cycling are explicitly coupled to anticipate bulk atmospheres and planetary redox evolution over 8 Gyr. By adopting a Monte Carlo approach that samples a broad range of initial conditions and unknown parameters, we make some tentative predictions about current Trappist-1 atmospheres. We find that anoxic atmospheres are probable, but not guaranteed, for the outer planets; oxygen produced via hydrogen loss during the pre-main sequence is typically consumed by crustal sinks. In contrast, oxygen accumulation on the inner planets occurs in around half of all models runs. Complete atmospheric erosion is possible but not assured for the inner planets (occurs in 20%-50% of model runs), whereas the outer planets retain significant surface volatiles in virtually all model simulations. For all planets that retain substantial atmospheres, CO${}_2$-dominated or CO${}_2$-O${}_2$ atmospheres are expected; water vapor is unlikely to be a detectable atmospheric constituent in most cases. There are necessarily many caveats to these predictions, but the ways in which they misalign with upcoming observations will highlight gaps in terrestrial planet knowledge.

Main text 16 pages, 11 figures

References in corpus (38)

• Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Extreme Water Loss and Abiotic O${}_2$ Buildup On Planets Throughout the Habitable Zones of M Dwarfs
• Observing the Atmospheres of Known Temperate Earth-sized Planets with JWST
• The Superluminous Transient ASASSN-15lh as a Tidal Disruption Event from a Kerr Black Hole
• The Detectability and Characterization of the TRAPPIST-1 Exoplanet Atmospheres with JWST
• Abiotic oxygen-dominated atmospheres on terrestrial habitable zone planets
• Geodynamics and Rate of Volcanism on Massive Earth-like Planets
• Predictions of the atmospheric composition of GJ 1132b
• Oxygen fugacities of extrasolar rocks: Evidence for an Earth-like geochemistry of exoplanets
• Impact of Clouds and Hazes on the Simulated JWST Transmission Spectra of Habitable Zone Planets in the TRAPPIST-1 System
• Detectability of atmospheric features of Earth-like planets in the habitable zone around M dwarfs
• Reconnaissance of the TRAPPIST-1 exoplanet system in the Lyman-$\alpha$ line
• On the Frequency of Potential Venus Analogs from Kepler Data
• A review of possible planetary atmospheres in the TRAPPIST-1 system
• Photochemistry of Anoxic Abiotic Habitable Planet Atmospheres: Impact of New H${}_2$O Cross-Sections
• TRAPPIST-1 Habitable Atmosphere Intercomparison (THAI). Motivations and protocol version 1.0
• Escape and fractionation of volatiles and noble gases from Mars-sized planetary embryos and growing protoplanets
• Abundant atmospheric methane from volcanism on terrestrial planets is unlikely and strengthens the case for methane as a biosignature
• The persistence of oceans on Earth-like planets: insights from the deep-water cycle
• Sensitive Probing of Exoplanetary Oxygen via Mid Infrared Collisional Absorption
• Was Venus Ever Habitable? Constraints from a Coupled Interior-Atmosphere-Redox Evolution Model
• The young Sun's XUV-activity as a constraint for lower CO${}_2$-limits in the Earth's Archean atmosphere
• Tidal Heating and the Habitability of the TRAPPIST-1 Exoplanets
• Habitability of Earth-like stagnant lid planets: Climate evolution and recovery from snowball states
• Distinguishing between wet and dry atmospheres of TRAPPIST-1 e and f
• O2- and CO-Rich Atmospheres for Potentially Habitable Environments on TRAPPIST-1 Planets
• An upper limit on late accretion and water delivery in the Trappist-1 exoplanet system
• Solar XUV and ENA-driven water loss from early Venus' steam atmosphere
• Oxygen False Positives on Habitable Zone Planets Around Sun-Like Stars
• Observing Isotopologue Bands in Terrestrial Exoplanet Atmospheres with the James Webb Space Telescope---Implications for Identifying Past Atmospheric and Ocean Loss
• Do the TRAPPIST-1 Planets Have Hydrogen-rich Atmospheres?
• Waterworlds Probably Do Not Experience Magmatic Outgassing
• A mirage of the cosmic shoreline: Venus-like clouds as a statistical false positive for exoplanet atmospheric erosion
• A Coupled Analysis of Atmospheric Mass Loss and Tidal Evolution in XUV Irradiated Exoplanets: the TRAPPIST-1 Case Study
• Runaway climate cooling of ocean planets in the habitable zone: a consequence of seafloor weathering enhanced by melting of high-pressure ice
• The Effect of Land Albedo on the Climate of Land-Dominated Planets in the TRAPPIST-1 System
• Improved Constraints for the XUV Luminosity Evolution of Trappist-1

Cited by in corpus (20)

• Thermal emission from the Earth-sized exoplanet TRAPPIST-1 b using JWST
• Constraining the Thickness of the Atmosphere of TRAPPIST-1 b from its JWST Secondary Eclipse Observation
• Plausible constraints on the range of bulk terrestrial exoplanet compositions in the Solar neighbourhood
• The erosion of large primary atmospheres typically leaves behind substantial secondary atmospheres on temperate rocky planets
• Implications of atmospheric nondetections for Trappist-1 inner planets on atmospheric retention prospects for outer planets
• Sporadic Spin-Orbit Variations in Compact Multi-planet Systems and their Influence on Exoplanet Climate
• The Cosmic Shoreline Revisited: A Metric for Atmospheric Retention Informed by Hydrodynamic Escape
• Stellar Models Also Limit Exoplanet Atmosphere Studies in Emission
• Self-limited tidal heating and prolonged magma oceans in the L 98-59 system
• High-Resolution spectral models of TRAPPIST-1e seen as a Pale Blue Dot for ELT and JWST observations
• Water versus land on temperate rocky planets
• Tracing the Inner Edge of the Habitable Zone with Sulfur Chemistry
• TOI-733 b: a planet in the small-planet radius valley orbiting a Sun-like star
• From CO${}_2$- to H${}_2$O-dominated atmospheres and back -- How mixed outgassing changes the volatile distribution in magma oceans around M dwarf stars
• Interaction of Trappist-1 exoplanets with coronal mass ejections: Joule heating, Poynting fluxes and the role of magnetic fields
• Carbon Cycle Imbalances on Arid Terrestrial Planets with Implications for Venus
• Assessment of a Physics-based Retrieval of Exoplanet Atmospheric Temperatures from Infrared Emission Spectra
• Resistive MHD Simulations of Stellar Wind-Magnetosphere Coupling in TRAPPIST-1e
• Possible favored Great Oxidation Event scenario on exoplanets around M-Stars with the example of TRAPPIST-1e
• Chemistry, Climate, and Transmission Spectra of TRAPPIST-1 e Explored with a Multimodel Sparse Sampled Ensemble