Comets and Asteroids Archives

ExoMars TGO image of comet 3I/ATLAS -- ESA

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Press Release

ExoMars And Mars Express Observe Interstellar Comet 3I/ATLAS

by Keith CowingOctober 7, 2025October 7, 2025

Between 1 and 7 October, ESA’s ExoMars Trace Gas Orbiter (TGO) and Mars Express spacecraft turned their eyes towards interstellar comet 3I/ATLAS, as it passed close to Mars.

Continuum-subtracted spectra of comet 3I obtained on August 28 and September 3+4. Three narrow FeI lines are detected on August 28 in this spectral range, FeI λ3719.93Å being the brightest iron line detected in our spectra. On the average spectrum obtained in September 3+4 (shifted vertically for clarity), the FeI lines are brighter, and four of them are detected. Broad emission features due to background [OII] emission at 3727Å and 3729Å are also observed. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Comets and Asteroids, Imaging & Spectroscopy, Interstellar, Status Report

Extreme NiI/FeI Abundance Ratio In The Coma Of The Interstellar Comet 3I/ATLAS

by Keith CowingOctober 2, 2025October 2, 2025

Emission lines of FeI and NiI are commonly found in the coma of solar system comets, even at large heliocentric distances.

IRAS 16293-2422 b -- European Southern Observatory

Astrochemistry, Astrogeology, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

The Interstellar Heritage Of Comets

by Keith CowingSeptember 30, 2025September 30, 2025

Comets have similar compositions to interstellar medium ices, suggesting at least some of their molecules maybe inherited from an earlier stage of evolution.

Impact event that killed the dinosaurs -- NSF

Biogeochemical Cycles & Geobiology, Comets and Asteroids, Extinction events, Gaia - Planetary Perspectives, Habitable Zones, Impact events, Meteorites & Asteroids, Status Report

The Depletion Of The Asteroid Belt And The Impact History Of The Earth

by Keith CowingSeptember 29, 2025September 28, 2025

We have evaluated the rate at which the asteroid belt is losing material, and how it splits between macroscopic bodies and meteoritic dust.

(a) Adsorption geometries of 3C on CO ice reflecting chemisorption and formation of the 3CCO complex on different binding sites at the DLPNO-CCSD(T)/CBS//MN15(D3BJ)/6-31+G(d,p) level. The individual values for the chemisorption energies are 54.0 kcal mol−1 for Site I, 54.0 kcal mol−1 for Site II and 53.0 kcal mol−1 for Site III. (b) Scheme of the CCO + CO −−→ C3O2 reaction at Site I after 3C chemisorption. -- astro-ph.GA

Astrochemistry, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Formation Of Unsaturated Carbon Chains Through Carbon Chemisorption On Solid CO

by Keith CowingSeptember 27, 2025June 10, 2026

The interaction of carbon atoms with solid carbon monoxide (CO) is a fundamental process in astrochemistry, influencing the formation of complex organic molecules in interstellar environments.

This study investigates the formation of carbon dioxide clathrate hydrates under conditions simulating interstellar environments, a process of significant astrophysical and industrial relevance. -- ACS Omega via PubMed

Astrochemistry, Astronomy & Telescopes, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Laboratory Studies Of The Clathrate Hydrate Formation In The Carbon Dioxide-Water Mixtures At Interstellar Conditions

by Keith CowingSeptember 25, 2025September 25, 2025

This study investigates the formation of carbon dioxide clathrate hydrates under conditions simulating interstellar environments, a process of significant astrophysical and industrial relevance.

Astrochemistry, Astrogeology, Comets and Asteroids, Conferences and Meetings, Icy Worlds, Missions & Hardware, Sample Return, Status Report

Workshop On Bennu And Ryugu: Samples From The Early Solar System

by Keith CowingSeptember 14, 2025September 15, 2025

The Workshop on Bennu and Ryugu: Samples from the Early Solar System is scheduled for October 7–9, 2025, at the Lunar and Planetary Institute (LPI) in Houston, Texas.

Multi-night ZTF stacks centered at the nominal ephemeris position of 3I of periods from UT 2024 June 15 to UT 2025 May 9. Each stack is smoothed by a 2′′-wide Gaussian function for clarity. The 3σ uncertainty ellipses (appeared largely as a thin line due to very small semi-minor axis) are plotted in the upper-right corner of each panel. The images are color-inverted. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Comets and Asteroids, Interstellar, Status Report

Prediscovery Activity of New Interstellar Object 3I/ATLAS: A Dynamically-Old Comet?

by Keith CowingSeptember 12, 2025September 12, 2025

We report on the prediscovery observations and constraints of the new interstellar comet 3I/2025 N1 (ATLAS), made by the Zwicky Transient Facility (ZTF), for the inbound leg of the comet […]

An SwRI-led team used Webb telescope observations (white) to detect methane gas on the distant dwarf planet Makemake. Sharp emission peaks near 3.3 microns reveal methane in the gas phase above Makemake’s surface. A continuum model (cyan) is overlaid for comparison; the gas emission peaks are identified where the observed spectrum rises above the continuum. An artistic rendering of Makemake’s surface is shown in the background. Courtesy of S. Protopapa, I. Wong/SwRI/STScI/NASA/ESA/CSA

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Press Release

Methane Gas Discovered On Makemake

by Keith CowingSeptember 11, 2025

A Southwest Research Institute-led team has reported the first detection of gas on the distant dwarf planet Makemake, using NASA’s James Webb Space Telescope (JWST). This discovery makes Makemake only […]