Impact events Archives

Example of alt-azimuth grid overlay on the Heredia dashboard camera video. Perspective lines on the road define the position of the horizon, and the orientation of a lamp post in different video frames (white lines left, slightly bend halfway up) and features on buildings (right) defines the rotation to normal. The flare elevation (assuming an altitude of 25.1 km) defines the scale. In this case, the camera's central azimuth changed over time and the meteor path in the central frame shown was adjusted using the meteor wake as guidance. -- astro-ph.EP

Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Impact events, Meteorites & Asteroids, Panspermia, Planetary Protection & Biosafety, Status Report

Orbit, Meteoroid Size, And Cosmic Ray Exposure History Of The Aguas Zarcas CM2 Breccia

by Keith CowingApril 2, 2025April 2, 2025

The Aguas Zarcas (Costa Rica) CM2 carbonaceous chondrite fell during night time in April 2019. Security and dashboard camera video of the meteor were analyzed to provide a trajectory, lightcurve, […]

Aguas Zarcas meteorite with irregular surface features. This 146g stone is on loan to the Buseck Center for Meteorite Studies from Michael Farmer. Photo: Arizona State University / SETI Institute.

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Impact events, Meteorites & Asteroids, Press Release

A Meteorite With Water-rich Minerals Lands On Earth In Good Condition

by Keith CowingApril 1, 2025April 1, 2025

In April 2019, rare primitive meteorites fell near the town of Aguas Zarcas in northern Costa Rica. In an article published online in the journal Meteoritics & Planetary Science, an […]

The effects of atmospheric entry on comets’ impact velocity at the surface (left), and remaining mass (right) is shown as a function of initial radius, and velocity for an Earth-like atmosphere (with surface density 1.225 kg m−3 ). For comets that fragment (i.e., with small initial radius), this is given as the (mass-weighted) average velocity, and total mass of fragments that reach the surface. There is a sharp transition in the response to the atmosphere at an initial radius of about 100 m, in agreement with analytical predictions (equation 6). -- astro-ph.EP

Comets and Asteroids, Exoplanets, -moons, -comets, Extinction events, Gaia - Planetary Perspectives, Impact events, Origin & Evolution of Life, Status Report

The Atmospheric Entry of Cometary Impactors

by Keith CowingMarch 31, 2025March 31, 2025

Cometary impacts play an important role in the early evolution of Earth, and other terrestrial exoplanets.

Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Impact events, Status Report, Titan, Water/Hycean Worlds & Oceanography

Impacts Into Titan’s Methane-clathrate Crust As A Source Of Atmospheric Methane

by Keith CowingMarch 27, 2025March 27, 2025

Titan is the only icy satellite in the solar system with a dense atmosphere. This atmosphere is composed primarily of nitrogen with a few percent methane, which supports an active, […]

The radiants in RA and Dec of the 472 fastest (vhel ≧ 44 km s−1 ) events along with the radiants of some known meteor showers and some relevant fiducial directions such as the Galactic Center. For the showers, the 10 most active annual IAU meteors showers that are seen by GMN (that is, that contain significant mm sized particles) and that have in-atmosphere speeds below 50 km/s. Directional values: the position of the Galactic Center (Reid & Brunthaler 2004); the Solar apex with respect to the Local Standard of Rest (LSR) (Jaschek & Valbousquet 1992); the Solar apex with respect to the Galactic frame (Solar Galactic Apex); and the interstellar dust (ISD) influx direction into the Solar System as reported by spacecraft Cassini, Ulysses, and Galileo, due to the motion of the Solar System through the Local Interstellar Cloud (LIC) (Sterken et al. 2012). No strong signature of the Galaxy or of meteor showers is seen. -- astro-ph.EP

Astrogeology, Comets and Asteroids, Imaging & Spectroscopy, Impact events, Interstellar, Meteorites & Asteroids, Panspermia, Planetary Protection & Biosafety, Status Report, Stellar Cartography

An Upper Limit on the Interstellar Meteoroid Flux at Video Sizes from the Global Meteor Network

by Keith CowingMarch 27, 2025March 27, 2025

Material arriving at our solar system from the Galaxy may be detected at Earth in the form of meteors ablating in our atmosphere. Here we report on a search for […]

Ordinary chondrites (OC) and meteorites belonging to the HED clan used in the present study -- astro-ph.EP

Astrochemistry, Astrogeology, Biosignatures & Paleobiology, Comets and Asteroids, Impact events, Meteorites & Asteroids, Status Report

Spectral Effects of Shock Darkening On Ordinary Chondrite and Howardite, Eucrite, And Diogenite Meteorites

by Keith CowingMarch 27, 2025March 27, 2025

Impacts are the most ubiquitous processes on planetary bodies in our solar system. During these impact events, shock waves can deposit enough energy to produce shock-induced darkening in the target […]

The “HCN machine”: Geological, atmospheric, meteoritic, and chemical processes synthesizing the building blocks of life on the Hadean Earth (artist’s impression, own creation, © Klaus Paschek).

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Habitable Zones, Impact events, Lava / magma ocean / Volcanic Worlds, Origin & Evolution of Life, Panspermia, Status Report, Water/Hycean Worlds & Oceanography

Deep Mantle-Atmosphere Coupling And Carbonaceous Bombardment: Options For Biomolecule Formation On Aan Oxidized Early Earth

by Keith CowingMarch 21, 2025March 21, 2025

Understanding what environmental conditions prevailed on early Earth during the Hadean eon, and how this set the stage for the origins of life, remains a challenge.

1D spherical vapor plume expansion and flow reversal. Example vapor plume evolution starting with an 80 GPa water sphere of radius 25 km, expanding into a dust-free nebular gas at 10−6 bars. In panels A-D, the thick dashed line represents the material boundary between the inner water vapor plume and outer nebular gas. The color shading presents radial velocity (A), pressure (B), density (C), and temperature (D) versus time. The streamlines (thin grey in A; thin white in B-D) indicate the flow history of the gas and any fully coupled dust. The nebular shock generated by the expanding vapor plume creates a transiently hot nebular environment that expands and cools on the time scale of hours. The inset (E) is a close-in view of the initial hot nebular shock front. In panel C, points A-E are used to illustrate size sorting in the outward flow in section 6. We propose chondrules form and cool in the transiently shocked (dusty) nebular gas. The supplemental materials contain an interactive version of this figure. -- astro-ph.EP

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Impact events, Meteorites & Asteroids, Status Report

Planetesimal Impact Vapor Plumes and Nebular Shocks Form Chondritic Mixtures

by Keith CowingMarch 14, 2025March 14, 2025

The origin of chondrules, and the chondritic sedimentary rocks that dominate the meteoritic record, is a long-standing problem in planetary science. Here, we develop a physical model for the formation […]

Curtin University researchers have discovered the world’s oldest known meteorite impact crater

Astrogeology, Biogeochemical Cycles & Geobiology, Extinction events, Fossils & Paleontology, Impact events, Mapping, Geodesy, Cartography, Bathymetry, Press Release

Earth’s Oldest Impact Crater Found, Rewriting Planetary History

by Keith CowingMarch 6, 2025March 6, 2025

Curtin University researchers have discovered the world’s oldest known meteorite impact crater, which could significantly redefine our understanding of the origins of life and how our planet was shaped.

Astrochemistry, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Biophysics, Fossils & Paleontology, Impact events, Interstellar, Press Release, Radiation, Water/Hycean Worlds & Oceanography

Evidence Of An Ancient Cosmic Event Deep In Earth’s Oceans

by Keith CowingFebruary 11, 2025February 11, 2025

Beryllium-10, a rare radioactive isotope produced by cosmic rays in the atmosphere, provides valuable insights into the Earth’s geological history.

Impact events

Orbit, Meteoroid Size, And Cosmic Ray Exposure History Of The Aguas Zarcas CM2 Breccia

A Meteorite With Water-rich Minerals Lands On Earth In Good Condition

The Atmospheric Entry of Cometary Impactors

Impacts Into Titan’s Methane-clathrate Crust As A Source Of Atmospheric Methane

An Upper Limit on the Interstellar Meteoroid Flux at Video Sizes from the Global Meteor Network

Spectral Effects of Shock Darkening On Ordinary Chondrite and Howardite, Eucrite, And Diogenite Meteorites

Deep Mantle-Atmosphere Coupling And Carbonaceous Bombardment: Options For Biomolecule Formation On Aan Oxidized Early Earth

Planetesimal Impact Vapor Plumes and Nebular Shocks Form Chondritic Mixtures

Earth’s Oldest Impact Crater Found, Rewriting Planetary History

Evidence Of An Ancient Cosmic Event Deep In Earth’s Oceans

Potential Survivable Niches For Microbial Life On The Lunar South Pole

JWST Telemetry Combined With Active Coronagraphy: Raw Contrast Predictions For Exoplanet Imaging With The Habitable Worlds Observatory

Antarctica Is Home To Microbes Found Nowhere Else On Earth

Study: Peptides Can Form Well-defined Structures In Harsh, Venus-like Conditions

Modeling Carbon-Based Planets with MAGRATHEA