TRAPPIST-1 Archives

This illustration shows the seven Earth-size planets of TRAPPIST-1, an exoplanet system about 40 light-years away, based on data current as of February 2018. The image shows the planets relative sizes but does not represent their orbits to scale. The art highlights possibilities for how the surfaces of these intriguing worlds might look based on their newly-calculated properties. The seven planets of TRAPPIST-1 are all Earth-sized and terrestrial. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it. Larger image

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Lava / magma ocean / Volcanic Worlds, Press Release, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Rocky Planets Orbiting Small Stars Could Have Stable Atmospheres Needed To Support Life

by Keith CowingOctober 25, 2024October 25, 2024

Since its launch in late 2021, NASA’s James Webb Space Telescope has raised the possibility that we could detect signs of life on exoplanets, or planets outside our solar system.

Illustration showing communication between planets beyond our solar system looking from the perspective of Earth. New research using the Allen Telescope Array looked for this type of communication, similar to communication between Earth and our rovers on Mars, in the TRAPPIST-1 star system. CREDIT Zayna Sheikh

Astronomy & Telescopes, Intelligence & Language, Press Release, SETI & Technosignatures, TRAPPIST-1

Are Nearby TRAPPIST-1 Planets Sending Radio Signals To Each Other?

by Keith CowingOctober 21, 2024October 21, 2024

A new technique allows astronomers to home in on planets beyond our solar system that are in line with each other and with Earth to search for radio signals similar, […]

An injection-recovery test using setigen used to score an isolated signal with the DOT algorithm. The isolated linearly-drifting signal seen in the target panel was injected in a region of frequency space known to contain only noise. The signal was given a width of 2 Hz, a drift rate of 0.07 Hz s−1 , and an SNR of 42,000. turboSETI calculates SNR independently from the SNR input into setigen, but nevertheless indicates a relatively strong signal as intended. The low correlation score of 0.019 indicates that the signal detected in the target panel is distinct from the pure noise in the off panel. -- astro-ph.IM

Astronomy & Telescopes, Biosignatures & Paleobiology, Press Release, SETI & Technosignatures, TRAPPIST-1

Scientists Use Allen Telescope Array to Search for Radio Signals in the TRAPPIST-1 Star System

by Keith CowingOctober 16, 2024October 16, 2024

Scientists at the SETI Institute and partners from Penn State University used the Allen Telescope Array (ATA) to search for signs of alien technology in the TRAPPIST-1 star system. The […]

Constraints on high mean molecular weight atmosphere compositions for TRAPPIST-1 c. Top panel: Combined visit 1+2 spectrum of TRAPPIST-1 c corrected by the best-fitting stellar contamination model (black points), and atmosphere models for deep 100 bar atmospheres composed of 100% H2O (blue), NH3 (green), CO (red), and CH4 (orange). Bottom panels: Marginalized posterior distributions on the effective surface pressure for different atmosphere compositions (labelled, with colours corresponding to the models in the top panel) The shaded areas correspond to the 1, 2, and 3σ upper limits obtained on the effective surface pressure in each composition scenario. 1-bar atmospheres (indicated by the dashed vertical lines) are ruled out at better than 2-σ for H2O, NH3, and CO-rich compositions. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Imaging & Spectroscopy, Status Report, TRAPPIST-1

Promise and Peril: Stellar Contamination and Strict Limits on the Atmosphere Composition of TRAPPIST-1c from JWST NIRISS Transmission Spectra

by Keith CowingOctober 3, 2024October 3, 2024

Attempts to probe the atmospheres of rocky planets around M dwarfs present both promise and peril. While their favorable planet-to-star radius ratios enable searches for even thin secondary atmospheres, their […]

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. […]

Comparison of the TRAPPIST-1 system to our inner solar system -- NASA (larger image)

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

Drifts Of The Sub-stellar Points Of The TRAPPIST-1 Planets

by Keith CowingSeptember 19, 2024September 19, 2024

Accurate modeling of tidal interactions is crucial for interpreting recent JWST observations of the thermal emissions of TRAPPIST-1~b and c and for characterizing the surface conditions and potential habitability of […]

Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, TRAPPIST-1

Updated Forecast For TRAPPIST-1 Times Of Transit For All Seven Exoplanets Incorporating JWST Data

by Keith CowingSeptember 19, 2024September 19, 2024

The TRAPPIST-1 system has been extensively observed with JWST in the near-infrared with the goal of measuring atmospheric transit transmission spectra of these temperate, Earth-sized exoplanets. A byproduct of these […]

Frequency coverage (x-axis) by day (y-axis) of the TRAPPIST-1 system observations using the Allen Telescope Array at Hat Creek Radio Observatory in Fall 2022. The standard radio frequency bands are shaded in the background and labeled. These observations covered a continuous 0.9–9.3 GHz in radio frequency, over two weeks in October– November 2022. -- astro-ph.EP

Astronomy & Telescopes, Biosignatures & Paleobiology, Intelligence & Language, SETI & Technosignatures, Status Report, TRAPPIST-1

A Radio Technosignature Search Of TRAPPIST-1 With The Allen Telescope Array

by Keith CowingSeptember 16, 2024September 16, 2024

Planet-planet occultations (PPOs) occur when one exoplanet occults another exoplanet in the same system as seen from the Earth’s vantage point. PPOs may provide a unique opportunity to observe radio […]

The condensation sequence for a solar composition atmosphere where dashed lines indicate the condensation curves for a variety of typically assumed condensable species. The model planet atmosphere day (red) and night (blue) temperature profiles are shown. In the case of a primordial solar composition atmosphere there may exist a favorable region of temperature phase space where we do not expect significant opacity from condensational clouds (at ∼ 400 - 800 K). However, given the presumed diversity of terrestrial atmospheres, such a favorable region may be unlikely to exist. -- astro-ph.EP

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

Nightside Clouds on Tidally-locked Terrestrial Planets Mimic Atmosphere-Free Scenarios

by Keith CowingSeptember 13, 2024September 13, 2024

We investigate the impact of nightside cloud formation on the observable night-day contrast of tidally-locked terrestrial planet atmospheres.

Top panels: evolution of CHZ and UVH for Trappist-1, Proxima Centauri, GJ 273, GJ 163, K2-18, GJ 832, GJ 357, GJ 229A, HD 40307 and Kepler-62. In each plot the vertical gray line represents the host star age found in the literature and the relative errors (the gray shaded region around the gray line). Yellow, orange and dark orange lines represent the ages at which fraction of systems with at least one rocky planet without a primordial envelope in the CHZ is equal to 20%, 30%, 40% for each system (according to NGPPS model). The dashed line represents the time where each star settled onto the main sequence. Bottom panels: evolution of the fraction of the radial extension of the CHZ that is overlapping the radial extension of the UVZ for three different values of the NUV atmospheric transmission. -- astro-ph.EP

Biophysics, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Proxima Centauri, Radiation, Space Weather & Heliophysics, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

The Time Evolution Of The Ultraviolet Habitable Zone

by Keith CowingSeptember 5, 2024September 5, 2024

For stars hosting Circumstellar Habitable Zone (CHZ) exoplanets, we investigate the time-evolution of their ultraviolet habitable zone (UHZ), the annular region around a star where an exoplanet could experience a […]

TRAPPIST-1

Rocky Planets Orbiting Small Stars Could Have Stable Atmospheres Needed To Support Life

Are Nearby TRAPPIST-1 Planets Sending Radio Signals To Each Other?

Scientists Use Allen Telescope Array to Search for Radio Signals in the TRAPPIST-1 Star System

Promise and Peril: Stellar Contamination and Strict Limits on the Atmosphere Composition of TRAPPIST-1c from JWST NIRISS Transmission Spectra

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

Drifts Of The Sub-stellar Points Of The TRAPPIST-1 Planets

Updated Forecast For TRAPPIST-1 Times Of Transit For All Seven Exoplanets Incorporating JWST Data

A Radio Technosignature Search Of TRAPPIST-1 With The Allen Telescope Array

Nightside Clouds on Tidally-locked Terrestrial Planets Mimic Atmosphere-Free Scenarios

The Time Evolution Of The Ultraviolet Habitable Zone

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