Astrophysical Journal Letters Archives

An SwRI-led study used NASA’s James Webb Space Telescope to compare interstellar comet 3I/ATLAS with icy bodies in our solar system. The comparison offers clues to the early formation of planetary building blocks. At top right, both 3I/ATLAS and the icy solar system comet C/2024 E1 show a strong water-ice absorption band near 3 microns, but the interstellar comet has very weak or missing bands near 1.5 and 2.0 microns. Its spectrum more closely resembles the average spectrum of a class of icy worlds beyond Neptune whose spectra also show carbon dioxide ice and organics (bottom right). The artist’s concept (left, not to scale) compares the relatively pure ice grains with separate dust, as interpreted for most solar system comets, with the dust-rich ice aggregates the study inferred for 3I/ATLAS. Both grain types are around a micron or smaller. Credit SwRI/Silvia Protopapa. Spectra: NASA/ESA/CSA JWST

Webb Space Telescope Used To Compare Interstellar Comet 3I/ATLAS With Icy Bodies In Our Solar System

by Keith CowingOctober 28, 2026October 28, 2026

[SwRI] A Southwest Research Institute-led study used NASA’s James Webb Space Telescope to examine ice grains streaming from interstellar comet 3I/ATLAS, just the third object from beyond our solar system […]

Astrophysical Journal Letters

Webb Space Telescope Used To Compare Interstellar Comet 3I/ATLAS With Icy Bodies In Our Solar System

Astrobiologist Dale Andersen’s Antarctic Field Report: 28 October 2026: Shoveling Snow In Antarctica

Webb Space Telescope Used To Compare Interstellar Comet 3I/ATLAS With Icy Bodies In Our Solar System

A New Database To Track Origins Of Water From Space

Offworld Agriculture

Mesoscale Modelling Of Titan’s Shangri-La region: The Impact Of Surface Properties On Winds