TRAPPIST-1 b Archives

Surface pressure-temperature (P-T) points for each atmosphere in our work for each planet.

Astrochemistry, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Status Report, TRAPPIST-1

Coupled Photochemical-Climate Modeling of Plausible Tenuous Outgassed Atmospheres on the TRAPPIST-1 Planets

by Keith CowingMay 16, 2026May 16, 2026

Available JWST observations TRAPPIST-1 system have suggested that several of the planets are likely airless, or possess a very tenuous atmosphere.

This artist’s impression displays TRAPPIST-1 and its planets reflected in a surface. The potential for water on each of the worlds is also represented by the frost, water pools, and steam surrounding the scene. © NASA/R. Hurt/T. Pyle

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Between Eternal Night And Day, The Faces Of Two Cousins Of The Earth

by Keith CowingApril 14, 2026April 14, 2026

Red dwarf stars—cooler and smaller than our Sun—make up more than 75% of the stars in our Galaxy. Astronomers have shown that small, Earth-like planets are common around this type […]

C.1: Same as Figure 4 but for the tidal temperature. These values are compared with the equilibrium temperature of all planets (full black circles) and the brightness temperature of T-1b and c (full red circles) estimated in Ducrot et al. (2020). We also give the recently acquired brightness temperatures measured by the JWST: the temperature of planet b comes from Greene et al. (2023), and that of planet c from Zieba et al. (2023). -- astro-ph.EP

Astrogeology, Exoplanets, -moons, -comets, Habitable Zones, Press Release, TRAPPIST-1

Estimation Of The Tidal Heating In The TRAPPIST-1 Planets. Influence Of The Internal Structure

by Keith CowingJanuary 8, 2026January 8, 2026

With the arrival of JWST observations of the TRAPPIST-1 planets, it is timely to reassess the contribution of tidal heating to their heat budget. JWST thermal phase curves could reveal […]

Final semi-major axes of satellites versus their initial orbital distance (in Hill radii) for TRAPPIST-1 e. -- astro-ph.EP

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

Orbital Stability Of Moons Around The TRAPPIST-1 Planets

by Keith CowingDecember 23, 2025December 23, 2025

We investigate the dynamical stability of potential satellites orbiting the seven planets of the TRAPPIST-1 system using a suite of N-body simulations.

Top: White light curves of observation 1, observation 3, and observation 15 from the NA reduction, both at native time resolution in black and binned to 25x in red for visibility. All transits are labeled by planet. Observation 1 also has a large flare that occurs right before the egress of planet e. Shown in the upper right is a schematic of our proposed setup, with the true overlapping planetary transit chords taken from Agol et al. (2021). Middle: Hα light curve from the NA reduction. Peaks in Hα correspond to flaring events, many of which are not visible in the white light curve, at least without hints to their location from the Hα signature. Note that the light curves are binned in time to 50x (to approximately 70 second bins) relative to that shown in the white light curve for visibility in the low signal single wavelengths shown. Bottom: Transmission spectrum of TRAPPIST-1 e (top) and TRAPPIST-1 b (bottom) for observation 1, observation 3, and observation 15 from left to right. -- astro-ph.EP

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

JWST TRAPPIST-1 e/b Program: Motivation and First Observations

by Keith CowingDecember 9, 2025December 9, 2025

One of the forefront goals in the field of exoplanets is the detection of an atmosphere on a temperate terrestrial exoplanet, and among the best suited systems to do so […]

Located about 39 light-years from Earth, the TRAPPIST system resembles a miniature version of our solar system: The star, an ultracool red dwarf, and all its planets would comfortably fit inside the orbit of planet Mercury. Credit NASA, ESA, CSA, STScI, Joseph Olmsted (STScI)

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release, Titan, TRAPPIST-1

A New Look At TRAPPIST-1e, An Earth-sized, Habitable-zone Exoplanet

by Keith CowingDecember 5, 2025December 5, 2025

Of the seven Earth-sized worlds orbiting the red dwarf star TRAPPIST-1, one planet in particular has attracted the attention of scientists, because it orbits the star within the “Goldilocks zone” […]

Core–mantle partition coefficient of oxygen as a function of pressure and temperature. Left: Experimental data for metal–silicate partitioning of O obtained at high pressures up to 104 GPa. Horizontal dashed line located at DO=0.83 indicates full oxidation of the core (see the main text), and therefore distinguishes ‘terrestrial’ from ‘coreless’ planets. It is clear that, within the investigated pressure range, DO asymptotically approaches the dashed line, but never reaches the core-free regime, albeit higher pressures and temperatures promote the sequestration of O into the metallic core, i.e. larger DO. Right: The same dataset for O partitioning plotted as a function of reciprocal temperature. Dashed lines are fitted results (Eq. 7) showing the dependence of O partitioning on temperature at a given pressure or vice versa. -- astro-ph.EP

Astrogeology, Exoplanets, -moons, -comets, Status Report, TRAPPIST-1

Limits On Forming Coreless Terrestrial Worlds In The TRAPPIST-1 System

by Keith CowingNovember 4, 2025November 4, 2025

With seven temperate Earth-sized planets revolving around an ultracool red dwarf, the nearby TRAPPIST-1 system offers a unique opportunity to verify models of exoplanet composition, differentiation, and interior structure.

Snapshots of VGS-calculated surface water mass (in units of Earth’s ocean mass) for TRAPPIST-1 analogs, shown as a function of total planet mass (M⊕) and final orbital distance (AU). Panel (a) depict planets at the halfway point of accretion (i.e., when the protoplanet reaches half its final mass), while panels (b) show the final planet properties. Measured properties of the TRAPPIST-1 planets are indicated by black circles (Agol et al. 2021). At mid-assembly, most inner planets are water-poor due to early impact-driven loss and higher irradiation. By the end of accretion, increased volatile delivery events from more water-rich materials and reduced erosion allow many planets, particularly beyond ∼0.03 AU,to accumulate and preserve large water reservoirs, leading to the strong radial gradient in water content. -- astro-ph.EP

Analog Studies, Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Born Dry or Born Wet? A Palette of Water Growth Histories in TRAPPIST-1 Analogs and Compact Planetary Systems

by Keith CowingOctober 15, 2025October 15, 2025

It is still unclear whether exoplanets in compact multiplanet systems such as TRAPPIST-1 are able to accrete large quantities of volatiles, grow to sufficient mass, and maintain robust atmospheres and […]

This chart shows, on the top row, artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii, masses, densities and surface gravity as compared to those of Earth. Credit: NASA/JPL-Caltech (larger image)

Analog Studies, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Desert Worlds, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, TRAPPIST-1

Born Dry or Born Wet? A Palette of Water Growth Histories in TRAPPIST-1 Analogs and Compact Planetary Systems

by Keith CowingSeptember 23, 2025September 23, 2025

Exoplanets under consideration for the Rocky Worlds DDT. Planets above the cosmic shoreline are expected to have lost their atmosphere. The circled exoplanets have already been observed in emission during JWST’s first three cycles. The exoplanets for which the observations concluded there is no atmosphere are in red. We also added the Solar System terrestrial planets. The XUV irradiation is computed from Zahnle & Catling (2017). -- astro-ph.EP

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

Constraints On The Possible Atmospheres On TRAPPIST-1 b: Insights From 3D Climate Modeling

by Keith CowingSeptember 3, 2025September 18, 2025

JWST observations of the secondary eclipse of TRAPPIST-1 b at 12.8 and 15 microns revealed a very bright dayside. These measurements are consistent with an absence of atmosphere. Previous 1D […]

TRAPPIST-1 b

Coupled Photochemical-Climate Modeling of Plausible Tenuous Outgassed Atmospheres on the TRAPPIST-1 Planets

Between Eternal Night And Day, The Faces Of Two Cousins Of The Earth

Estimation Of The Tidal Heating In The TRAPPIST-1 Planets. Influence Of The Internal Structure

Orbital Stability Of Moons Around The TRAPPIST-1 Planets

JWST TRAPPIST-1 e/b Program: Motivation and First Observations

A New Look At TRAPPIST-1e, An Earth-sized, Habitable-zone Exoplanet

Limits On Forming Coreless Terrestrial Worlds In The TRAPPIST-1 System

Born Dry or Born Wet? A Palette of Water Growth Histories in TRAPPIST-1 Analogs and Compact Planetary Systems

Born Dry or Born Wet? A Palette of Water Growth Histories in TRAPPIST-1 Analogs and Compact Planetary Systems

Constraints On The Possible Atmospheres On TRAPPIST-1 b: Insights From 3D Climate Modeling

Roman Space Telescope: Enabling Images Of Distant Worlds

NASA Solar System Exploration Research Virtual Institute (SSERVI) Cooperative Agreement Notice (NNH26ZDA016C) Final Text And Due Dates

Interstellar Aromatic Infrared Bands: IR Absorption Spectroscopy Of The Lowest Triplet State Of Naphthalene

The Highly Unusual Behavior And Chemical Composition Of Interstellar Comet 2I/Borisov

Volatile Depletion In Rocky Planets As A Chemical Fingerprint Of Hybrid Accretion