Impact events Archives

Conceptualization of Nankoweap landslide that brought down large boulders of Kaibab Limestone from the cliffs at left and created a geologically short-lived paleolake in Grand Canyon. Credit Karl Karlstrom

Astrogeology, Atmospheres, Climate, Weather, Caves, Craters, Mountains, Subsurface, Lava Tubes, Impact events, Meteorites & Asteroids, Press Release

Link Established Between A Grand Canyon Landslide And The Meteor Crater Impact Event

by Keith CowingJuly 16, 2025July 16, 2025

Geology is full of detective stories about Earth’s history, and a new paper in Geology by University of New Mexico Distinguished Professors Emeritus Karl Karlstrom and Laurie Crossey, along with […]

Schematic depiction of a bow shock flow. Meteoroid entry results in the bow shock wave (red line). The box illustrates stream lines around the object. Heated medium due to the bow shock immediately cools down with expansion process. Turbulent flow happens at the tail region through a growth of an instability, leading to mixing of material ablated from the projectile with the atmosphere. -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Impact events, Meteorites & Asteroids, Status Report, Titan

Modeling Atmospheric Alteration on Titan: Hydrodynamics and Shock-Induced Chemistry of Meteoroid Entry

by Keith CowingJuly 16, 2025July 16, 2025

Meteoroid entry into planetary atmospheres generates bow shocks, resulting in high-temperature gas conditions that drive chemical reactions.

The peak temperature achieved by all tracer particles in simulations of a 1 km diameter comet impacting at 10 km s−1 (left) and 40 km s−1 (right) in a provenance plot, where the tracers are shown at their initial locations prior to the impact. A solid black line is shown between the two halves of the figure to delineate the difference between the two simulations. The 10 km s−1 impact on the left shows a peak temperature of ∼ 8900 K, whereas the 40 km s−1 impact on the right achieves a peak temperature of ∼ 74 000 K. Although the range of temperatures achieved during the two impacts is vastly different, the distribution of temperatures is similar, with a sharp increase in temperatures at the leading edge and raised temperatures towards the centre of the body. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Impact events, Status Report

Constraining The Survival Of HCN During Cometary Impacts

by Keith CowingJuly 14, 2025July 14, 2025

Cometary impacts have been invoked as an atmosphere-independent method of stockpiling hydrogen cyanide (HCN), a key prebiotic feedstock molecule, into environments favourable for the onset of prebiotic chemistry on the […]

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). […]

Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Extinction events, Fossils & Paleontology, Gaia - Planetary Perspectives, Impact events, Meteorites & Asteroids, Press Release

New Fossils From Earth’s Most Famous Extinction Show Climate Tipping Point Was Crossed

by Keith CowingJuly 4, 2025July 4, 2025

The collapse of tropical forests during Earth’s most catastrophic extinction event was the primary cause of the prolonged global warming which followed, according to new research.

Scheme of a geothermal valley between two snow-covered Hadean volcanoes. The fumaroles, thermal springs, apron pools, and terracettes are shown based on the reconstruction of the 3.48 Ga old Hadean geothermal system. On the right, various reactions of CO2 sequestration in a Hadean volcanic system are indicated, see Section 3.2.5 and Section 3.2.6. Inserts: (A) volcanic fumaroles, image from https://home.nps.gov/articles/000/fumaroles.htm, credit: USGS. (B) Schematic cross section of a pH-neutral hot spring, redrawn with modifications from [341,342]. (C) White Terraces of New Zealand as an example of volcanic terracettes (painted by Charles Bloomfield in 1884, two years before the terraces were buried under the waters of the lake Rotomahana following the eruption of Mt. Tarawera. Image credit: Museum of New Zeeland, https://collections.tepapa.govt.nz/object/42254, accessed on 23 December 2024.). (D) Interconversion of nitriles, amides, and ammonium salts of organic acids, represented by their simplest species, in geothermal pools in the presence of inorganic catalysts; each of the nitrogen-containing compounds shown is considered as a substrate for further synthetic reactions. Formamide and other amides, as the least volatile components, may have sustained/buffered the whole system. -- Life via PubMed

Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Extinction events, Fossils & Paleontology, Genomics, Proteomics, Bioinformatics, Habitable Zones, Impact events, Moon, Origin & Evolution of Life, Status Report

Origin Of The RNA World In Cold Hadean Geothermal Fields Enriched In Zinc And Potassium – Abiogenesis As A Positive Fallout From The Moon-Forming Impact?

by Keith CowingJuly 1, 2025July 1, 2025

The ubiquitous, evolutionarily oldest RNAs and proteins exclusively use rather rare zinc as transition metal cofactor and potassium as alkali metal cofactor, which implies their abundance in the habitats of […]

Impact on a 3 Gyr-old Earth-sized planet with a small core Rc = 0.2R and L = 25 km (a) and 100 km (b). In each panel, the left half displays the melt fraction and the right half the melting mechanism, with the materials shown at their pre-impact positions. Basaltic crust is shown in light gray and dunitic mantle material in medium-shaded gray. The melt generation farther than 5L from the center of the melt region below the impact point (approximated by z = L) is neglected. -- astro-ph.EP

Astrogeology, Biogeochemical Cycles & Geobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Impact events, Mapping, Geodesy, Cartography, Bathymetry, Status Report

The Influence Of Interior Structure And Thermal State On Impact Melt Generation Upon Large Impacts Onto Terrestrial Planets

by Keith CowingJune 25, 2025June 25, 2025

We investigate the melt production of planetary impacts as a function of planet size (R/REarth=0.1-1.5), impactor size (L=1-1000 km), and core size ratio (Rcore/R=0.2-0.8) using a combination of parameterized convection […]

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’ […]

A clay-rich mesa in the Hellas basin of Mars. The blue color near the rim is aluminum bearing clays. The red-orange color below that is iron and magnesium bearing clays. The image captures an area that’s 1 kilometer across. Credit: NASA/JPL-Caltech/UArizona.

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Impact events, Lava / magma ocean / Volcanic Worlds, Mapping, Geodesy, Cartography, Bathymetry, Mars, Origin & Evolution of Life, Press Release

Thick Clay Layers On Mars May Have Been A Stable Place For Ancient Life

by Keith CowingJune 18, 2025June 18, 2025

The planet Mars is home to thick layers of clay that can span hundreds of feet. Since they need water to form, these outcrops have long been of interest to […]

This image shows a wide-field view of part of the Taurus Molecular Cloud, about 450 light-years from Earth. Its relative closeness makes it an ideal place to study the formation of stars. Many dark clouds of obscuring dust are clearly visible against the background stars. Credit: Digitized Sky Survey 2. Acknowledgment: Davide De Martin.

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Impact events, Interstellar, Status Report

How Do Organic Molecules Survive in Space?

by Keith CowingJune 10, 2025June 10, 2025

The discovery of small polycyclic aromatic hydrocarbon (PAH) molecules in interstellar clouds through radio astronomy and observations of infrared (IR) emission bands from PAHs with unprecedented sensitivity by the James […]