NIMS Archives

Time-resolved IR spectra from electron irradiation of CaCO3 at 50, 100, and 120 K under two electron fluxes, normalized to the preirradiation CaCO3 baseline and truncated to the 4.2–4.3 μm region to highlight the CO2 ν3 band. Vertical dashed lines mark the central wavelengths of the CO2 doublet, determined from double Gaussian fits to the continuum-removed spectra (gray). CO2 absorptions appear upon irradiation and gradually saturate. The strongest absorptions occur at 50 K under high flux. At higher temperatures, the absorptions are weaker, but radiolytic CO2 production is still apparent. -- astro-ph.EP

Astrochemistry, Astrogeology, Europa, Icy Worlds, Imaging & Spectroscopy, Status Report

Formation And Trapping Of CO2 From Cryogenic Irradiation Of Carbonate

by Keith CowingMay 2, 2026May 2, 2026

The detection of CO2 on the Jovian satellite Europa by Galileo NIMS and recent mapping of the leading side by JWST has revealed that it is most concentrated in geologically […]

Global mosaic of Europa showing the locations of Pwyll and Manann´an craters. Pwyll crater, one of Europa’s youngest impact features, is ∼27 km in diameter, surrounded by a dark ring of proximal ejecta, and has an extensive bright ray ejecta which extends as far as 1000 km and stands in stark contrast to the darker reddish surface of Europa’s trailing hemisphere. Manann´an crater is ∼23 km in diameter, also has a dark, red ring of proximal ejecta, and is surrounded by a much less extensive bright ray system which extends up to ∼120 km and covers nearby young terrain including chaos terrains in Dyfed Regio and the triple band Belus linea. The location of the trailing hemisphere apex (0◦ N, 270◦ W) is indicated with a star. This mosaic map, created by Steve Albers, blends an existing color map from NASA/JPL/Bj¨orn J´onsson created using color images from Voyager and Galileo, the high-resolution black and white mosaic from USGS, and additional higher resolution imagery from Galileo and Juno. -- astro-ph.EP

Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Europa, Icy Worlds, Imaging & Spectroscopy, Impact events, Mapping, Geodesy, Cartography, Bathymetry, Space Weather & Heliophysics, Status Report

Pwyll and Manannán Craters as a Laboratory for Constraining Irradiation Timescales on Europa

by Keith CowingApril 25, 2024April 25, 2024

We examine high spatial resolution Galileo/NIMS observations of the young (~1 My – 20 My) impact features, Pwyll and Manannán craters, on Europa’s trailing hemisphere in an effort to constrain […]