rocky planet Archives

An artist's concept illustrates a dusty planet-forming disk -- NASA

Astrochemistry, Astrogeology, Exoplanets, -moons, -comets, Mars, Mercury, Meteorites & Asteroids, Status Report, Venus

Homogeneous Accretion Of The Earth In The Inner Solar System

by Keith CowingApril 17, 2026April 17, 2026

Meteorites are classified as either non-carbonaceous- (NC) or carbonaceous (CC), representing bodies that likely formed in the inner- or outer solar system, respectively. Despite its location in the inner solar […]

Fully corrected and calibrated albedos of Titan (yellow), Saturn (green), Uranus (blue), and Neptune (red) covering 0.3 µm to 2.1 µm, offset for clarity. Regions of strong telluric absorption are masked in lighter shades, and it should be noted that they are less reliably corrected. The flat regions in the UV were flagged as bad pixels in all images by X-shooter. We also highlight a vertical discontinuity between the VIS and NIR arms of Titan, which is likely due to weather inconsistency. The colors used for these objects are the same in the following figures. -- Astronomy & Astrophysics

Astrochemistry, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Jupiter, Mars, Mercury, Neptune, Saturn, Status Report, Titan, Uranus

HiDef Neighbors: Solar System Objects As Exoplanet Analogs I. Gaseous Objects, Planets, Planetary Systems, And Small Bodies

by Keith CowingMarch 27, 2026

Context. Intermediate-resolution spectral observations are vital tools for characterizing the composition and physical properties of Solar System bodies in detail. At present, the planets and moons of our Solar System […]

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 […]

Normalized torques as a function of planetary mass and semimajor axis, assuming circular and coplanar orbits. The different migration regimes are indicated, separating inward from outward migration. The mass required to open a gap in the disk (dashed white line), the planet-to-star mass ratio (q) of 0.002, and the gas depth criterion K = 104 are over-plotted (dashed black lines). -- astro-ph.EP

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

Formation Of Cold Giant Planets Around Late M Dwarfs Via Core Accretion And The Fate Of Inner Rocky Worlds

by Keith CowingDecember 11, 2025December 10, 2025

Modeling the formation of cold giant planets around M dwarfs is difficult because their disks may not contain enough solids to form massive cores and because forming giants are expected […]

(left) This zoomed-in image of Uranus, captured by Webb’s Near-Infrared Camera (NIRCam) Feb. 6, 2023. The planet displays a blue hue in this representative-color image, made by combining data from two filters (F140M, F300M) at 1.4 and 3.0 microns, which are shown here as blue and orange, respectively.(right) Webb’s Near-Infrared Camera (NIRCam) image of Neptune, taken on July 12, 2022, brings the planet’s rings into full focus for the first time in more than three decades. -- NASA/STSCI

Astrogeology, Atmospheres, Climate, Weather, Ice Giant, Magnetic Fields, Electromagnetism, bioelectricity,, Neptune, Press Release, Uranus

Uranus And Neptune Might Be Rock Giants

by Keith CowingDecember 10, 2025December 10, 2025

The planets in the Solar System are typically divided into three categories based on their composition: the four terrestrial rocky planets (Mercury, Venus, Earth and Mars), followed by the two […]

Exoplanets with masses error and radii error less than 25%. Symbol size is proportional to mass. Colors correspond to equilibrium temperatures calculated with bond albedos of 0.3 and redistribution factors of 4. Colors are loosely binned according to physical processes: planets with icy surfaces should they have any water (0-273 K), planets that allow for liquid water (273-373 K), planets that are in runaway greenhouse below the critical point of water (373-670K), hot planets that cannot have water clouds (670-1200K) and magnetic effects on their atmospheres are negligible, hot planets where magnetic effects like ohmic dissipation are important, very hot planets where magnetic effects are less important (due to full ionization and freezing to magnetic field). Solar system planets are labeled and shown as black symbols for reference. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Gas Giants, Ice Giant, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Diversity Of Exoplanets

by Keith CowingMay 16, 2025

This review article delves into the study of low-mass exoplanets: super-Earths, mini-Neptunes and the new categories within and between that we are starting to discover.

Earth as seen by the Apollo 11 crew -- NASA

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Gaia - Planetary Perspectives, Mars, Moon, Status Report

Earth’s Composition: Origin, Evolution and Energy Budget

by Keith CowingMay 7, 2025May 7, 2025

One in every two atoms in the Earth, Mars, and the Moon is oxygen; it is the third most abundant element in the solar system.

The crew of the Enterprise vies a map of the Sigma Draconis system and its three Class M planets - "Spock's Brain" - Paramount/CBS.

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Icy Worlds, Lava / magma ocean / Volcanic Worlds, Nomenclature, Systematics, Natural History, Science Fiction, Status Report, Stellar Cartography, Water/Hycean Worlds & Oceanography

Architecture Classification For Extrasolar Planetary Systems

by Keith CowingFebruary 22, 2025February 22, 2025

This paper presents a classification framework for the architectures of planetary systems based on a complete survey of the confirmed exoplanet population.

Modelled planet-to-star fluxes The 15 Fp/F* simulations shown assume an airless, rocky exoplanet with a homogeneous surface temperature and a surface composition equivalent to each laboratory-measured rock sample in this study. R = 100. The PHOENIX stellar model of red dwarf LHS 3844 and the planetary parameters of its close-in rocky planet LHS 3844b were used as a representative star–planet system. The black body curve was calculated using the LHS 3844 PHOENIX stellar model and a planetary black body. Inset, Magnification of the Fp/F* models for three representative samples: relatively fresh, unaltered basalt LC10; amphibole-rich sample SE20; and serpentinized sample TO01. Dots are simulated MIRI LRS observations of a surface composed of sample SE20. High and low error bars show the estimated observation precision, assuming five eclipse observations of a planet like LHS 3844b, binned to R = 20 (Methods). The LRS simulation highlights the expected spectral deviation among the three basaltic samples near 10 μm. Symbols at top right are a reminder of which samples come from the same locality (as indicated by the symbol shape). The 15 modelled flux line colours correspond to symbol colours. Source data -- Nature astronomy

Astrogeology, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Potential For Observing Geological Diversity From Mid-infrared Spectra Of Rocky Exoplanets

by Keith CowingNovember 19, 2024November 19, 2024

The James Webb Space Telescope can potentially explore the geological diversity of the surfaces of rocky exoplanets, especially due to its access to mid-infrared wavelengths.

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 […]