micrometeorite Archives - Astrobiology

HAADF image and quantified EDX map (at%) of a GEMS-like assemblage in UCAMM DC06- 18, which is located at the top of the FIB section, probably close to the external surface of the UCAMM. - [astro-ph.EP]

Meteorites & Asteroids

STXM-XANES And TEM Analysis Of UltraCarbonaceous Antarctic MicroMeteorites (UCAMMs)

by Keith CowingAugust 28, 2026August 28, 2026

[astro-ph.EP] The Concordia micrometeorite collection contains UltraCarbonaceous Antarctic MicroMeteorites (UCAMMs) of probable cometary origin. Eight FIB sections of UCAMMs were studied by Scanning Transmission X-ray Microscopy – X-ray Absorption Near […]

Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) characterization of the micrometeorites. (A-C) SEM images of the micrometeorites. (D-F) close up SEM images corresponding to (A-C). A: Porphyritic (PO), B: scoriaceous (ScMM), C: barred olivine (BO) (G-I) SEM-EDX spectra of the meteorites (intensity in counts versus energy in keV). Element assignments for each peak were provided by the instrument. Quantification of the elemental composition is presented below each spectrum. Elements which constitute more than 10% of the total are highlighted in the tables. Oxygen was not determined. -- biorxiv.org

Genomics, Proteomics, Bioinformatics, Meteorites & Asteroids, Origin & Evolution of Life, Status Report

Protocell Formation On Micrometeorites

by Keith CowingApril 14, 2025April 14, 2025

We report on the formation of membranous protocells by self-assembly of lipids on micrometeorites, the extraterrestrial particles that have been continuously reaching the surface of the Earth ever since its […]

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 […]

Secondary electron (SE) SEM images of a CI (a and c) and CM (b and d) simulant pellet before and after irradiation. Panels a and b show images of the fresh material, while panels c and d are of representative laser-irradiated regions. The white scale bar at the lower left side of each panel corresponds to 2 𝜇𝑚 in length. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Meteorites & Asteroids, Space Weather & Heliophysics, Status Report

Laser Irradiation of Carbonaceous Chondrite Simulants: Space Weathering Implications for C-complex Asteroids

by Keith CowingApril 19, 2024

Surfaces of carbonaceous asteroids (C-complex) have shown diverse contrasting spectral variations, which may be related to space weathering.

a, Backscattered electron image of a fine Ryugu grain. The white boxes correspond to the areas shown in b and c. b, Secondary electron image of framboidal magnetite showing granular texture. c, Secondary electron image of porous iron sulfide surrounded by phyllosilicate. The arrow points to an iron whisker on the iron sulfide surface. Sample ID is A0104-021012.

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Meteorites & Asteroids, Origin & Evolution of Life, Press Release

Meteorites Were A Likely Source Of Nitrogen For Early Earth

by Keith CowingDecember 2, 2023December 2, 2023

Micrometeorites originating from icy celestial bodies in the outer Solar System may be responsible for transporting nitrogen to the near-Earth region in the early days of our solar system. That […]