TRAPPIST-1e Archives

Schematic representation of the effect of stellar contamination (TLS) with actual examples of the effect of TLS in simulated signals.

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Stellar Cartography

Efficient Reduction Of Stellar Contamination And Noise In Planetary Transmission Spectra Using Neural Networks

by Keith CowingFebruary 27, 2026February 27, 2026

Context: JWST has enabled transmission spectroscopy at unprecedented precision, but stellar heterogeneities (spots and faculae) remain a dominant contamination source that can bias atmospheric retrievals if uncorrected.

The incident photon flux density for the modern-day Earth (black), Archean Earth at 2.65 Ga (blue), and TRAPPIST-1e (red). The spectral resolution has been reduced for clarity. The shaded regions represents three relevant bandpasses for photosynthesis: standard PAR (0.40-0.70 µm), extended PAR (0.40-0.75 µm), and anoxic PAR (0.40-1.1 µm). -- astro-ph.EP

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Origin & Evolution of Life, Radiation, Space Weather & Heliophysics, Status Report, Terraforming & Geoengineering, TRAPPIST-1

Dearth of Photosynthetically Active Radiation Suggests No Complex Life on Late M-Star Exoplanets

by Keith CowingJanuary 7, 2026January 7, 2026

The rise of oxygen in the Earth’s atmosphere during the Great Oxidation Event (GOE) occurred about 2.3 billion years ago. There is considerably greater uncertainty for the origin of oxygenic […]

K2-18 b vertical velocity 𝜔 at the 0.01 bar level. Negative (positive) 𝜔 indicates upwards (downwards) motion. The global overturning circulation is clearly visible. Irradiation concentrated on the dayside heats and expands these atmospheric regions, driving upwards motion. There is corresponding subsidence on the nightside. -- astro-ph.EP

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

A New Convection Scheme For GCMs Of Temperate Sub-Neptunes

by Keith CowingFebruary 19, 2025February 19, 2025

Atmospheric characterisation of temperate sub-Neptunes is the new frontier of exoplanetary science with recent JWST observations of possible Hycean world K2-18b.

Schematic overview of coupled redox-atmosphere-interior evolution model, PACMAN-P. The model is initialized with a completely molten mantle, and the solidification radius, rs, evolves from the core-mantle boundary to the surface, rp, as the planet cools. At each timestep, we calculate multiphase thermochemical equilibrium between C, H, O, and Fe-bearing species to find the mantle redox state and the partitioning of volatiles between the magma ocean and the atmosphere. Surface climate, Tsurf, is calculated using a radiative-convective model given atmospheric volatile inventories. Under highly reducing conditions created by large H2 envelopes, the reaction of H2 with the silicate magma ocean produces metallic iron, that is either sequestered in the core or remains in the mantle (two endmember assumptions). Atmospheric escape is either XUV-limited or diffusion limited depending on stratospheric composition, and under the former regime we calculate the hydrodynamic drag of O and CO. -- astro-ph.EP

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

The Erosion Of Large Primary Atmospheres Typically Leaves Behind Substantial Secondary Atmospheres On Temperate Rocky Planets

by Keith CowingOctober 1, 2024October 1, 2024

Exoplanet exploration has revealed that many–perhaps most–terrestrial exoplanets formed with substantial H2-rich envelopes, seemingly in contrast to solar system terrestrials, for which there is scant evidence of long-lived primary atmospheres. […]

Zonally and temporally averaged zonal wind profiles for both our model with the sub-stellar point placed over the ocean (SSPO - left) and sub-stellar point placed over land/Africa (SSPL - right). Here eastwards winds are shown in shades of blue whilst westwards winds are shown in shades of red. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

How Land-Mass Distribution Influences the Atmospheric Dynamics of Tidally Locked Terrestrial Exoplanets

by Keith CowingJuly 14, 2024July 7, 2024

Interpretation of the ongoing efforts to simulate the atmospheres of potentially-habitable terrestrial exoplanets requires that we understand the underlying dynamics and chemistry of such objects to a much greater degree […]

Horizontal slices of the O3 number density for our TRAPPIST-1e model at a pressure (altitude) of a) 103 hPa (∼15 km) and b) 609 hPa (∼5 km). The substellar point is at 180° longitude and 0° latitude. N represents the North pole and S represents the South pole. Lower panels show the polar projections. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Press Release, TRAPPIST-1

Asymmetries In The Simulated Ozone Distribution On TRAPPIST-1e Due To Orography

by Keith CowingJuly 6, 2024July 6, 2024

TRAPPIST-1e is a tidally locked rocky exoplanet orbiting the habitable zone of an M dwarf star. Upcoming observations are expected to reveal new rocky exoplanets and their atmospheres around M […]

Maps of surface temperature (colors) and 430 hPa winds (arrows) for each GCM simulation with all CO2 cases (each column) having independent color bars. The substellar point is located at (0◦ , 0◦ ). The substellar point is hottest at lower obliquities, and the poles are hotter than the equator at higher obliquities. Day-night surface temperature contrasts and resulting planetary-scale atmospheric wave patterns, like Rossby gyres, are more prominent for the cases with less CO2. For the higher obliquity cases the direction of the equatorial wind speed reverses from eastward to westward. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Habitable Zones, Imaging & Spectroscopy, Status Report, TRAPPIST-1

The Coupled Impacts of Atmospheric Composition and Obliquity on the Climate Dynamics of TRAPPIST-1e

by Keith CowingMay 13, 2024May 13, 2024

Planets in multi-planet systems are expected to migrate inward as near-resonant chains, thus allowing them to undergo gravitational planet-planet interactions and possibly maintain a non-zero obliquity.

Oxygen retention efficiency as a function of initial water content in TO. Top Row: Interior planets, T1-b, c, and d. Bottom Row: Outer planets, T1-e, f, g, and h. Coloring shows the percentage of simulations at a particular initial water content that fell in a given oxygen retention efficiency bin (e.g., each column corresponds to one initial water content and sums to 100%). Contours are given for the 50th percentile values (solid white lines) and the 1σ confidence region (dashed white lines). -- astro-ph.EP

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

The Implications of Thermal Hydrodynamic Atmospheric Escape on the TRAPPIST-1 Planets

by Keith CowingMay 7, 2024May 7, 2024

JWST observations of the 7-planet TRAPPIST-1 system will provide an excellent opportunity to test outcomes of stellar-driven evolution of terrestrial planetary atmospheres, including atmospheric escape, ocean loss and abiotic oxygen […]

Shows the CH4 production rate from ecosystem 1 for the 3.8 Ga Earth (dashed) and TRAPPIST-1e (solid) case. The CH4 production rate is split between anoxic H2 (purple) and CO (grey) consumers. the total of these is also shown (green) This plot used simulations with the reduced network. -- astro-ph.EP

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

Biosignatures From Pre-oxygen Photosynthesising Life On TRAPPIST-1e

by Keith CowingApril 18, 2024April 18, 2024

In order to assess observational evidence for potential atmospheric biosignatures on exoplanets, it will be essential to test whether spectral fingerprints from multiple gases can be explained by abiotic or […]

Time mean thermodynamic and circulation regime in our simulations. (a–d) Surface temperature in K overlaid by streamlines of the horizontal wind at ≈8 km above the surface. (e–h) Top-of-atmosphere outgoing longwave radiation in W m−2 . (i–l) Zonal mean of the eastward wind (orange contours, m s−1 ) overlaid by the day-side upward wind (red and blue contours, cm s−1 ). -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Status Report, TRAPPIST-1

The Impact Of The Explicit Representation Of Convection On The Climate Of A Tidally Locked Planet In Global Stretched-mesh Simulations

by Keith CowingMarch 3, 2024March 3, 2024

Convective processes are crucial in shaping exoplanetary atmospheres but are computationally expensive to simulate directly.

TRAPPIST-1e

Efficient Reduction Of Stellar Contamination And Noise In Planetary Transmission Spectra Using Neural Networks

Dearth of Photosynthetically Active Radiation Suggests No Complex Life on Late M-Star Exoplanets

A New Convection Scheme For GCMs Of Temperate Sub-Neptunes

The Erosion Of Large Primary Atmospheres Typically Leaves Behind Substantial Secondary Atmospheres On Temperate Rocky Planets

How Land-Mass Distribution Influences the Atmospheric Dynamics of Tidally Locked Terrestrial Exoplanets

Asymmetries In The Simulated Ozone Distribution On TRAPPIST-1e Due To Orography

The Coupled Impacts of Atmospheric Composition and Obliquity on the Climate Dynamics of TRAPPIST-1e

The Implications of Thermal Hydrodynamic Atmospheric Escape on the TRAPPIST-1 Planets

Biosignatures From Pre-oxygen Photosynthesising Life On TRAPPIST-1e

The Impact Of The Explicit Representation Of Convection On The Climate Of A Tidally Locked Planet In Global Stretched-mesh Simulations

A New Earth-like Exoplanet Discovered

Curiosity Rover Takes a Close Look at Martian Sulfur Crystals

Unraveling The Building Blocks Of Earth’s Pigments

Astrochemical Study of Early Embedded Discs

A Panspermia Origin For Venus Cloud Life