Terrestrial Planet Archives

Evolution of the number of planets in one system averaged over 20 runs, ⟨Np⟩. The horizontal axes are the time normalized by the Kepler period of the innermost planet in each model. (a) model R1 (0.05–0.15au) and (b) model R3 (0.5–1.5au). -- astro-ph.EP

Astrogeology, Exoplanets, -moons, -comets, Impact events, Status Report

Semi-analytical Model For The Dynamical Evolution Of Planetary Systems via Giant Impacts

by Keith CowingMay 28, 2025May 28, 2025

In the standard model of terrestrial planet formation, planets are formed through giant impacts of planetary embryos after the dispersal of the protoplanetary gas disc.

This artist’s concept of the large Quetzalpetlatl Corona located in Venus’ southern hemisphere depicts active volcanism and a subduction zone, where the foreground crust plunges into the planet’s interior. A new study suggests coronae are the locations of several types of tectonic activity. Credit: NASA/JPL-Caltech/Peter Rubin

Astrogeology, Atmospheres, Climate, Weather, Imaging & Spectroscopy, Lava / magma ocean / Volcanic Worlds, Mapping, Geodesy, Cartography, Bathymetry, Missions & Hardware, Press Release, Venus

Lava World Recon: Possible Tectonic Activity On Venus

by Keith CowingMay 16, 2025May 16, 2025

Using archival data from the mission, launched in 1989, researchers have uncovered new evidence that tectonic activity may be deforming the planet’s surface.

Engineers at OHB, Germany, inspect Plato’s newly installed 24 cameras on the spacecraft’s optical bench, the structure that keeps all cameras firmly pointed in the right direction. -- ESA Larger images

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, PLATO, Press Release

Cameras Installed On Terrestrial Planet Hunter Plato

by Keith CowingMay 14, 2025April 27, 2026

The activities to assemble the European Space Agency’s Plato mission are progressing well now that 24 of the spacecraft’s 26 cameras have been installed. Once in space, Plato will use […]

Formation and growth of the disk. Gas surface densities (in g cm-2 ) for the inner 200 AU of the disk are shown at 13, 21, 30, 40, 50 and 60 kyr in (a) – (f). -- astro-ph.GA

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Exoplanets, -moons, -comets, Habitable Zones, Interstellar, Status Report

Habitable Worlds Formed at Cosmic Dawn

by Keith CowingFebruary 25, 2025February 25, 2025

Primordial supernovae were the first, great nucleosynthetic engines in the Universe, forging the elements required for the later formation of planets and life.

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

Dynamics of the Beta Pictoris Planetary System and Possibility of an Additional Planet

by Keith CowingFebruary 22, 2025February 22, 2025

The Beta Pictoris system is characterized by a dusty debris disk, in addition to the presence of two already known planets. This makes it a particularly interesting case for studying […]

Schematic illustrating transport mechanisms of volatiles that produce the C/H enhancement seen within the CO snowline in HD 163296 as observed by Zhang et al. (2020). The process begins in the outer disc with dust growing to pebbles as the CO and water vapour freeze out onto the pebbles. As the grains grow, they decouple from the gas and drift inwards towards the CO snowline; within the snowline, the CO sublimates and enhances the C/H ratio of the gas and vapour present; the CO vapour is transported to the upper layers of the disc via diffusion. It also advects inwards, indicated by the grey arrows. Water ice remains on the pebbles and is transported further inward as the pebbles continue to drift toward the water snowline, which is around 1 AU in our model in this paper. Here, water sublimates and becomes readily available for planet formation in the region where terrestrial planets may be forming. Note that the illustrated emission line probe region is specific to CO rotational lines in this context. This schematic was inspired by Fig. 2 of Cuzzi & Zahnle (2004). -- astro-ph.EP

Astrochemistry, Astrogeology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Status Report

The CO-Fuelled Time Machine: Tracing Birth Conditions and Terrestrial Planet Formation Outcomes in HD 163296 through Pebble Drift-induced CO Enhancements

by Keith CowingJanuary 11, 2025January 11, 2025

The architecture and composition of planetary systems are thought to be strongly influenced by the transport and delivery of dust and volatiles via ices on pebbles during the planet formation […]

The GCE-corrected, differential elemental abundance relative to the Sun ([X/Fe]solar - [X/Fe]star). The five solar twins with -0.1 < [Fe/H] < 0.1 dex, ∆ Teff < 100 K, ∆ log g < 0.1 are TOI-1055, TOI-2426, TOI-744, TOI-755, and TOI-818, are shown as gray symbols in the background, while the colored symbols show the average elemental abundance for these stars. Refractory elements are shown in orange, volatile elements are shown in blue symbols. Elements with Tc above 1300 K are considered refractory, with the threshold Tc of 1300 K shown by a dashed orange line. We fit a linear regression to the colored symbols while considering the error bars. The orange line displays the best linear fit to all the colored points, with the shaded blue band indicating the 1-σ confidence interval. The expression for the linear regression is -6.726e-05+2.320e−05 −2.342e−05 × Tc (K) + 0.086+0.030 −0.030. -- astro-ph.SR

Astrochemistry, Astronomy & Telescopes, Imaging & Spectroscopy, Space Weather & Heliophysics, Status Report, Stellar Cartography

High Precision Stellar Chemical Abundance for 17 Planet-hosting Stars and the Condensation Temperature Trend

by Keith CowingNovember 24, 2024November 24, 2024

The Sun is depleted in refractory elements compared to nearby solar twins, which may be linked to the formation of giant or terrestrial planets.

Schematic view of the interior of terrestrial planets showing major chemical layers (i.e., the crust, the mantle, and the core subdivided into an outer liquid and an inner solid core). For each terrestrial planet the surface elevation is shown with the same color scale for comparison using orthographic projection. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Mars, Mercury, Moon, Status Report, Venus

Terrestrial Planet Surfaces And Interiors

by Keith CowingNovember 19, 2024November 19, 2024

Rocky planets in our Solar System, namely Mercury, Venus, Earth, Mars, and the Moon, which is generally added to this group due to its geological complexity, possess a solid surface […]

Snapshots showing the dynamical evolution of the Solar System in the Grand Tack model. The four gas giants are represented by the black filled circles. Jupiter starts fully formed while the other giants planets grow. Terrestrial planetary embryos are represented by open circles. Water-rich and water-poor planetesimals/asteroids are shown by blue and red small dots, respectively. During the inward migration phase Jupiter shepherds planetesimals and planetary embryos, thus creating a confined disk around 1 AU. Saturn encounters Jupiter and both planets start to migrate outwards at about 100 kyr. During the outward migration phase the giant planets scatter planetesimals inward and repopulate the previously depleted belt with a mix of asteroids originated from different regions. Figure reproduced from Walsh et al. (2011Snapshots showing the dynamical evolution of the Solar System in the Grand Tack model. The four gas giants are represented by the black filled circles. Jupiter starts fully formed while the other giants planets grow. Terrestrial planetary embryos are represented by open circles. Water-rich and water-poor planetesimals/asteroids are shown by blue and red small dots, respectively. During the inward migration phase Jupiter shepherds planetesimals and planetary embryos, thus creating a confined disk around 1 AU. Saturn encounters Jupiter and both planets start to migrate outwards at about 100 kyr. During the outward migration phase the giant planets scatter planetesimals inward and repopulate the previously depleted belt with a mix of asteroids originated from different regions. Figure reproduced from Walsh et al. (2011). -- astro-ph.EP). -- astro-ph.EP

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

Formation Of Terrestrial Planets

by Keith CowingNovember 18, 2024November 18, 2024

Our understanding of the process of terrestrial planet formation has grown markedly over the past 20 years, yet key questions remain. This review begins by first addressing the critical, earliest […]

Planetary formation -- Grok via Astrobiology.com

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

Did The Terrestrial Planets Of The Solar System Form By Pebble Accretion?

by Keith CowingNovember 15, 2024November 15, 2024

The dominant accretion process leading to the formation of the terrestrial planets of the Solar System is a subject of intense scientific debate. Two radically different scenarios have been proposed.

Terrestrial Planet

Semi-analytical Model For The Dynamical Evolution Of Planetary Systems via Giant Impacts

Lava World Recon: Possible Tectonic Activity On Venus

Cameras Installed On Terrestrial Planet Hunter Plato

Habitable Worlds Formed at Cosmic Dawn

Dynamics of the Beta Pictoris Planetary System and Possibility of an Additional Planet

The CO-Fuelled Time Machine: Tracing Birth Conditions and Terrestrial Planet Formation Outcomes in HD 163296 through Pebble Drift-induced CO Enhancements

High Precision Stellar Chemical Abundance for 17 Planet-hosting Stars and the Condensation Temperature Trend

Terrestrial Planet Surfaces And Interiors

Formation Of Terrestrial Planets

Did The Terrestrial Planets Of The Solar System Form By Pebble Accretion?

Robotic Lava Tube Mapping And Multimodal Data Collection Using Quadruped And LiDAR

Thickly Frosted Polar Gullies On Mars

From Meteorites to Membrane Rafts: Ganglioside-Incorporating Prebiotic Vesicles and the Emergence of Membrane Domain Organization

Pandora Mission Begins A Study Of Exoplanets And Their Host Stars

JWST Reveals A Race Against Time For Forming Planets