Mercury Archives

Initial structure of the Impact Plume 60 s post impact. The impactor strikes from the left, at a 60° angle from horizontal, with the sun located to the right.There is a visible asymmetry in the plume due to the direction of impact; the “hole” on the right side of the plume is a bubble in this 2D slice of a fully 3D plume due to the removal of water vapor-rock mixtures from the simulation during the sampling from SOVA into DSMC codes (Prem et al. 2015). (Top) the plume contains a region of high density (~1022 molecules/m3 ) just above the point of impact, which rapidly drops toward the edges of the plume. (Bottom, left) The high plume densities correspond to short mean free paths for the vapor molecules. (Bottom, right) Comparing this mean free path with the length scale of the density gradient reveals very small Knudsen numbers throughout; the entire plume (except for the very outermost edges) is clearly within the continuum flow regime at this time, rather than the slip-flow, Knudsen, or Free Molecular regimes. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Comets and Asteroids, Cryobiology, Icy Worlds, Imaging & Spectroscopy, Impact events, Mapping, Geodesy, Cartography, Bathymetry, Mercury, Status Report

Transport of Water In A Transient, Impact-Generated Atmosphere On Mercury

by Keith CowingJune 5, 2026June 26, 2026

Mercury’s polar cold traps host water ice deposits that are likely populated with impact-delivered water via Mercury’s exosphere.

An artist's impression of a disk of gas and dust formed during the birth of the sun. Credit: NASA/FUSE/Lynette Cook

Astrochemistry, Astrogeology, Comets and Asteroids, Exoplanets, -moons, -comets, Habitable Zones, Mars, Mercury, Meteorites & Asteroids, Press Release, Venus

New Experiments And Modeling On Iron Meteorites Provide Insight Into Young Solar System And Earth’s Building Blocks

by Keith CowingJune 4, 2026June 4, 2026

Habitable planets require life-essential elements, like nitrogen and phosphorus. Understanding how those elements ended up in a planetary body can give insight into the formation of the solar system and […]

Model prediction for the water budget of the 4 terrestrial planets

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Habitable Zones, Mars, Mercury, Status Report, Venus

Astrochemical Inheritance of Terrestrial Planets Water from Local Wet Silicates

by Keith CowingMay 1, 2026May 5, 2026

The delivery of water to the inner Solar System rocky planets, including Earth, remains debated, as standard models assume that they formed from dry grains, inside the snowline of the […]

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 […]

The Pale Blue Dot is a photograph of Earth taken Feb. 14, 1990, by NASA’s Voyager 1 at a distance of 3.7 billion miles (6 billion kilometers) from the Sun. The image inspired the title of scientist Carl Sagan's book, "Pale Blue Dot: A Vision of the Human Future in Space," in which he wrote: "Look again at that dot. That's here. That's home. That's us." The above image, “Pale Blue Dot Revisited,” was created in 2020 for the 30th anniversary of the iconic picture. The updated version used modern image-processing software and techniques to revisit the well-known Voyager view, while attempting to respect the original data and intent of those who planned the images. NASA/JPL-Caltech Larger image

Imaging & Spectroscopy, Interstellar, Jupiter, Mars, Mercury, Neptune, Press Release, Uranus, Venus

Pale Blue Dot Anniversary

by Keith CowingFebruary 14, 2026February 14, 2026

The Pale Blue Dot is a photograph of Earth taken on Feb. 14, 1990, by NASA’s Voyager 1 spacecraft. Earth appears as a tiny speck of light suspended in a […]

Eccentricity and position snapshots over time of a simulation using the mixed scenario where all 4 terrestrial planets fit constraints and the Earth analogue had a final CC embryo impact. Snapshots are shown over time, including the moment after the final giant impact. The initial NC embryos and planetesimals are shown with the embryos in black and the planetesimals in orange, as well as the CC embryos and planetesimals in blue with Jupiter and Saturn in black on the far right. The final snapshot is the real solar system. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Extinction events, Impact events, Mars, Mercury, Moon, Status Report, Venus

Dynamical Origin Of Theia, The Last Giant Impactor On Earth

by Keith CowingJuly 4, 2025July 4, 2025

Cosmochemical studies have proposed that Earth accreted roughly 5-10% of its mass from carbonaceous (CC) material, with a large fraction delivered late via its final impactor, Theia (the Moon-forming impactor). […]

Impact history should play a crucial role in the search for habitable exoplanets like Earth -- SwRI

Astrochemistry, Astrogeology, Exoplanets, -moons, -comets, Impact events, Lava / magma ocean / Volcanic Worlds, Mars, Mercury, Press Release, Venus

Notable Progress In Understanding The Evolution Of The Terrestrial Planets

by Keith CowingJune 18, 2025June 18, 2025

An SwRI-led team compared the early impact history of Venus and Earth, determining that Venus experienced higher-energy impacts that created a superheated core. Models show these conditions could create Venus’ […]

Panel a: spatial distribution of 95th percentile values of ice contingency (at depth >5 m; light blue shaded area) and of Th concentration (yellow shaded area labeled with capital letters). Dashed red rectangles delimit the most seismically active regions according to the InSight mission (Ceylan et al., 2023). Panel b: intersection of the two previous maps. Yellow and red shaded areas (labeled with A and B) show the regions where values of both the 95th percentile and 99th percentile of Cv(5, long,lat) and [Th](long,lat) coincide. The faint white dots show the spatial distribution of pitted cones structures (modified from Mills et al., 2024). The black dots show the spatial distribution of candidate and confirmed SRLs according to Mcewen et al., (2021); Stilmann et al., (2016), and Oijha et al., (2014). The red dot shows the McLaughlin Crater with exposed carbonate rocks and signs of groundwater activity (Michalski et al., 2013). Gray in the background shows the Mars topography based on MOLA -- astro-ph.E

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Mercury, Microbiology & Virology, Status Report

Potential Habitability of Present-day Mars Subsurface for Terrestrial-like Methanogens

by Keith CowingNovember 25, 2024November 25, 2024

The intense debate about the presence of methane in the Martian atmosphere has stimulated the study of methanogens adapted to terrestrial habitats that mimic Martian environments.

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 […]