TRAPPIST-1 Archives

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Status Report, Water/Hycean Worlds & Oceanography

An Earth-like Density For The Temperate Earth-sized Planet GJ 12b

by Keith CowingJune 27, 2025June 27, 2025

While JWST has provided us with the opportunity to probe the atmospheres of potentially-habitable planets, observations of the TRAPPIST-1 system have shown us that active stars severely complicate efforts at […]

Astronomy & Telescopes, Atmospheres, Climate, Weather, Habitable Zones, Space Weather & Heliophysics, Status Report, TRAPPIST-1

Hubble’s Multi-Year Search for Exospheres in the TRAPPIST-1 System Reveals Frequent Microflares

by Keith CowingJune 17, 2025June 17, 2025

Ly-α observations provide a powerful probe of stellar activity and atmospheric escape in exoplanetary systems.

TRAPPIST-1 System contains multiple rocky planets in very tight orbits. In contrast, our solar system is much more expansive and has no planets inside the orbit of Mercury. -- NASA

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release, Stellar Cartography, TRAPPIST-1

New SwRI Model Explains Exoplanetary Systems With Compact Orbits

by Keith CowingJune 9, 2025June 9, 2025

Star and planet formation has largely been considered separate, sequential processes. But in a new study, scientists at Southwest Research Institute (SwRI) have modeled a different scenario where planets start […]

JWST GO time allocation for exoplanet science on different Cycles. Representation of the total General Observer (GO) allocated time for exoplanet science on JWST Cycle 1 (released on March, 2021, i.e., pre-launch), Cycle 2 (released on May 2023), Cycle 3 (released on February, 2024) and Cycle 4 (released on March, 2025). The percentage of all telescope time spent on exoplanet science for a given Cycle is indicated on top of this illustration (e.g., Cycle 1 comprised 23% of time on the telescope devoted to exoplanet science). The purple shading corresponds to the share allocated to transiting exoplanet science while the orange shading corresponds to highcontrast exoplanet science performed with JWST. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Status Report

Highlights from Exoplanet Observations by the James Webb Space Telescope

by Keith CowingMay 28, 2025May 28, 2025

The James Webb Space Telescope (JWST) has started a revolution in exoplanetary science.

This schematic depicts the set-up of the volatile exchange during initialization (t=0) and run time. For initialization, a surface temperature of 4000 K and a completely molten magma ocean is assumed, where the dissolved volatiles are in balance with the outgassed volatile content, set by the volatile melt fraction Fi . As the magma ocean solidifies, part of the volatile budget is deposited in the solid mantle. Further, atmospheric escape can remove H2O. These two sink terms thus reduce the amount of a volatile available in the fully coupled magma ocean-atmosphere system Mmoa i . The full overview of all included processes, including radiogenic heating, is shown in Barth et al. (2021, Fig. 1) -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Lava / magma ocean / Volcanic Worlds, Press Release, TRAPPIST-1

From CO2- to H2O-dominated Atmospheres And Back — How Mixed Outgassing Changes The Volatile Distribution In Magma Oceans Around M Dwarf Stars [TRAPPIST-1]

by Keith CowingMay 24, 2025May 24, 2025

We investigate the impact of CO2 on TRAPPIST-1 e, f and g during the magma ocean stage. These potentially habitable rocky planets are currently the most accessible for astronomical observations.

Schematic diagram of steps in the theoretical model. Further description of key parameters, sampled ranges, and calculation procedures is found in Methods. -- astro-ph.EP)

Exoplanets, -moons, -comets, Habitable Zones, Status Report, TRAPPIST-1

Statistical Geochemical Constraints On present-day Water Outgassing As A Source Of Secondary Atmospheres On The TRAPPIST-1 Exoplanets

by Keith CowingMay 8, 2025September 18, 2025

The TRAPPIST-1 planetary system is observationally favorable for studying if planets orbiting M stars can retain atmospheres and host habitable conditions. Recent JWST secondary eclipse observations of TRAPPIST-1 c rule […]

Temporal medians of ’Extreme’, ’Moderate’, and ’Quiescent’ simulations for Temperature (T in K). Medians are taken from 8 years and for (a) 1.223 × 10−5 mbar and (b) 0.008 mbar atmospheric levels. Extreme and Moderate medians are only taken for days when flares occur. Stippling uses a two-tailed Wilcoxon rank-sum test to represent ’Extreme’ and ’Moderate’ areas that are not statistically different from the ’Quiescent’ one at p

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Space Weather & Heliophysics, Status Report, Stellar Cartography, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Effects of Transient Stellar Emissions On Planetary Climates Of Tidally-locked Exo-earths

by Keith CowingMay 7, 2025May 7, 2025

Space weather events in planetary environments sourced from transient host star emissions, including stellar flares, coronal mass ejections, and stellar proton events, can substantially influence an exoplanet’s climate and atmospheric […]

Sketch of the magnetospheric interaction in the TRAPPIST-1–TRAPPIST-1e system. The stellar wind velocity and IMF streamlines are drawn in green and white, respectively. The M dwarf star is shown as a yellow sphere, and the planet TRAPPIST-1e as a blue shaded circle. The planetary magnetic field lines (white) exhibit compression on the dayside and extension into a magnetotail. A bow shock structure forms upstream of the planet under a super-Alfvénic regime. The color scale represents normalized plasma density. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Space Weather & Heliophysics, Status Report, TRAPPIST-1

MHD Simulations Preliminarily Predict The Habitability and Radio Emission of TRAPPIST-1e

by Keith CowingApril 24, 2025April 24, 2025

As the closest Earth-like exoplanet within the habitable zone of the M-dwarf star TRAPPIST-1, TRAPPIST-1e exhibits a magnetic field topology that is dependent on space weather conditions.

Left, difference in wmf between two different hydrosphere assumptions and the default model. Red dotted is models with the surface temperature raised to create a layer of liquid water instead of ice Ih. Blue dashed is models with the AQUA compilation of EoSs from Haldemann et al. (2020). The hatched region shows the 1-σ region of wmf from observational uncertainties with our default model. Right, difference in wmf between planet models with different bulk moduli for the mantle or core and our default planet model. In red, the bulk modulus of the core is increased (dotted) and decreased (dashed) by 10%. In blue, the bulk modulus of the bridgmanite and post perovskite is increased/decreased by 10%. -- astro-ph.EP

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

Uncertainties In The Inference of Internal Structure: The Case of TRAPPIST-1 f

by Keith CowingApril 24, 2025April 24, 2025

We use the TRAPPIST-1 system as a model observation of Earth-like planets. The densities of these planets being 1-10% less than the Earth suggest that the outer planets may host […]

Surface temperature (straddling 0◦C), total cloud cover (%), net outgoing thermal radiation (W m−2 ), and cloud water content (kg m−2 ) for four of the simulations listed in Table 1. Simulations are displayed from dry (Sim 01: Arid-Venus), semidry 10 m GEL (Sim 02: 10 m-Venus), Earth-like 310 m GEL (Sim 03: 310 m-Venus) and an aquaplanet (Sim 06). Sims 01–03 are 1 bar N2 dominated with 400ppmv CO2. Sim 06 is N2-dominated, but the only greenhouse gas is H2O following Wolf (2017). Cloud coverage is fairly low in Sims 01–02 as expected given limited surface reservoirs and cloud water content (rightmost column), and is much higher for Sims 03 and 06. -- astro-ph.EP

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Press Release, TRAPPIST-1, Venus

TRAPPIST-1 d: Exo-Venus, Exo-Earth or Exo-Dead?

by Keith CowingFebruary 10, 2025February 10, 2025

TRAPPIST-1 d is generally assumed to be at the boundary between a Venus-like world and an Earth-like world, although recently published works on TRAPPIST-1 b and c raise concerns that […]

TRAPPIST-1

An Earth-like Density For The Temperate Earth-sized Planet GJ 12b

Hubble’s Multi-Year Search for Exospheres in the TRAPPIST-1 System Reveals Frequent Microflares

New SwRI Model Explains Exoplanetary Systems With Compact Orbits

Highlights from Exoplanet Observations by the James Webb Space Telescope

From CO2- to H2O-dominated Atmospheres And Back — How Mixed Outgassing Changes The Volatile Distribution In Magma Oceans Around M Dwarf Stars [TRAPPIST-1]

Statistical Geochemical Constraints On present-day Water Outgassing As A Source Of Secondary Atmospheres On The TRAPPIST-1 Exoplanets

Effects of Transient Stellar Emissions On Planetary Climates Of Tidally-locked Exo-earths

MHD Simulations Preliminarily Predict The Habitability and Radio Emission of TRAPPIST-1e

Uncertainties In The Inference of Internal Structure: The Case of TRAPPIST-1 f

TRAPPIST-1 d: Exo-Venus, Exo-Earth or Exo-Dead?

A Martian Horizon Last Monday Afternoon

Habitable-zone Earths At The Detection Frontier: Measured Completeness And False-alarm Rate Of A Transit Pipeline For The PLATO M-dwarf Sample

A Homogeneous Survey Of JWST MIRI Transmission Spectra Of 10 Exoplanets

Retrieving Ocean Glint Reflectance Signatures From Directly Imaged Earth-like Exoplanets

Analytical Platform (Microsampling, Catapulting, Trapping, and LIBS) for the Characterization of Discrete Domains in Samples of Astrochemical Interest