Terrestrial Planet Archives - Page 6 of 7 - Astrobiology

Constraining the surface heterogeneities of a host star. a. A simulated 3.3-d full rotation curve of TRAPPIST-1 (black line) featuring nine transits of six planets (coloured lines). b. A snapshot of the spot distribution at the last rotational phase of the simulation shown in panel a, with the transit chords of planets b, c, d, and e. c. Contaminated transmission spectra for the same transit train of planets b–e (coloured lines). A nominal planet radius of 1 R⊕ (dashed gray line) is used for each planet to ease comparisons of the TLS effect for each planet. d. The residual stellar contamination signals for the simulated transits of planets c–e (coloured lines), after correcting for the TLS effect using the in-transit signal from planet b. A median-subtracted model of an atmosphere (see Figure 2) is shown for comparison (gray dashed line). e. Close-up view of the transit profiles for the four-planet transit train, highlighting repeated occultations of the same active regions by planets b and d as well as c and e, whose transit chords overlap in this simulation. -- astro-ph.EP

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

A Roadmap To The Efficient And Robust Characterization Of Temperate Terrestrial Planet Atmospheres With JWST

by Keith CowingNovember 1, 2023November 1, 2023

Ultra-cool dwarf stars are abundant, long-lived, and uniquely suited to enable the atmospheric study of transiting terrestrial companions with JWST. Amongst them, the most prominent is the M8.5V star TRAPPIST-1 […]

The blue, orange, and red crosses represent the averaged RV of stars due to Earth-like planets located at the IHZ, CHZ, and OHZ, respectively. The green crosses represent the maximum RV of Earth-like planets at the IHZ, with an inclination of 90◦ . The right panel shows the histogram of the RV expectation and the CDF. -- astro-ph.EP

Exoplanets, -moons, -comets, Habitable Zones, Status Report, Water/Hycean Worlds & Oceanography

The Potential of Detecting Nearby Terrestrial Planets in the HZ with Different Methods

by Keith CowingOctober 24, 2023October 24, 2023

Terrestrial planets in the habitable zone around nearby stars are of great interest and provide a good sample for further characteristics of their habitability.

Mercury

Mercury, Press Release

The Origin Of Mercury’s Structure and Chemical Composition and Their Astrobiological Implications

by Keith CowingOctober 17, 2023October 17, 2023

Mercury can be categorized as either an endmember or an outlier planet due to its unusually large iron core, constituting approximately 70% of its total mass. The origin of this […]

Experimentally measured outgassing composition of a 3 mg powdered Murchison sample from 200 °C–1200 ◦ C under a high-vacuum environment (∼10−4 Pa at lower temperatures and ∼10−3 Pa at higher temperatures; lower panel) compared with the outgassing trends of S and Zn under the same vacuum conditions from this study (upper panel). In the lower panel, the outgassing composition is shown as mole fractions of different outgassed species on a log scale as a function of temperature. The outgassing composition of Murchison was determined using a residual gas analyzer mass spectrometer that monitored the abundances (i.e., mole fractions) of the highly volatile outgassing species H2O, H2, CO, CO2, and H2S (see Thompson et al. 2021 for further details). Each species is labeled, and its mass number (in amu) is in parentheses. The dashed curves show equilibrium model-adjusted experimental outgassing compositions, which are the result of taking Thompson et al.’s (2021) experimental elemental outgassing results at intervals of 50 ◦ C and inputting those into the chemical equilibrium model of Figure 5 (see Schaefer & Fegley 2007, 2010 for details on the model) to recompute how the gas composition would speciate under equilibrium conditions. The upper panel shows the S and Zn outgassing trends from this study, expressed as these elements’ intensities, normalized to V and the average of the two unheated Murchison samples, for the residues heated under vacuum. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Meteorites & Asteroids, Status Report

Outgassing Composition of the Murchison Meteorite: Implications for Volatile Depletion of Planetesimals and Interior-atmosphere Connections for Terrestrial Exoplanets

by Keith CowingOctober 4, 2023October 4, 2023

Outgassing is a central process during the formation and evolution of terrestrial planets and their atmospheres both within and beyond the solar system.

The phased light curve of LTT 1445A, highlighting the transit of planet c. The detrended TESS observations are show in black and our new HST observations in orange. In blue, we show our MAP orbital solution. -- astro-ph.EP

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

HST/WFC3 Light Curve Confirms the Closest Exoplanet to Transit an M Dwarf is Terrestrial

by Keith CowingJuly 7, 2023July 7, 2023

Previous studies of the exoplanet LTT 1445Ac concluded that the light curve from the Transiting Exoplanet Survey Satellite (TESS) was consistent with both grazing and non-grazing geometries. As a result, […]

Ellipticity of Earth and Mars following the giant impact assuming an impact angle of 24.6◦ . Conservation of momentum requires that the Earth was deflected by 33.6◦ by the impact while Mars rebounded at an angle of 70.5◦ relative to the primordial eclyptic of the Sun’s axis. The Sun’s ecliptic was subsequently shifted by 7.2◦ leading to the current axial tilts of Earth and Mars. -- astro-ph.EP

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

The Origin Of The Terrestrial Planets

by Keith CowingMay 31, 2023May 31, 2023

Three major planets, Venus, Earth, and Mercury formed out of the solar nebula. A fourth planetesimal, Theia, also formed near Earth where it collided in a giant impact, rebounding as […]

An example detection of a planet

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Predicting the Yield of Small Transiting Exoplanets around Mid-M and Ultra-Cool Dwarfs in the Nancy Grace Roman Space Telescope Galactic Bulge Time Domain Survey

by Keith CowingMarch 20, 2023

We simulate the yield of small (0.5-4.0 R⊕) transiting exoplanets around single mid-M and ultra-cool dwarfs (UCDs) in the Nancy Grace Roman Space Telescope Galactic Bulge Time Domain Survey.

aplanet

Exoplanets, -moons, -comets, Habitable Zones, Press Release

The Planet That Could End Life On Earth

by Keith CowingMarch 7, 2023March 7, 2023

A terrestrial planet hovering between Mars and Jupiter would be able to push Earth out of the solar system and wipe out life on this planet, according to a UC […]

Terrestrial

Exoplanets, -moons, -comets, Status Report

Terrestrial Planet Formation From A Ring

by Keith CowingMarch 1, 2023

It has been long proposed that, if all the terrestrial planets form within a tiny ring of solid material at around 1 AU, the concentrated mass-distance distribution of the current […]

Terrestrial planets

Exoplanets, -moons, -comets, Habitable Zones, Press Release, Venus

The Demographics Of Terrestrial Planets In The Venus Zone

by Keith CowingFebruary 8, 2023February 8, 2023

Understanding the physical characteristics of Venus, including its atmosphere, interior, and its evolutionary pathway with respect to Earth, remains a vital component for terrestrial planet evolution models and the emergence […]