Astrophysics > Earth and Planetary Astrophysics arxiv.org/abs/2603.20445
[Submitted on 20 Mar 2026]
Roth, N. X. Cordiner, M. Milam, S. et al. Isotopic Signature of Organic Molecules from Beyond the Solar System: An Enriched Methane D/H Ratio in the Interstellar Object 3I/ATLAS
[Submitted on 20 Mar 2026] arxiv.org/abs/2603.20460
Roth, N. X. Cordiner, M. A. Milam, S. N. et al. Coma Physics of an Interstellar Object: JWST Spatial-Spectral Mapping of 3I/ATLAS
[Submitted on 24 Mar 2026] arxiv.org/abs/2603.23240
Biver, N. Bockelée-Morvan, D. Moreno, R. et al. Perihelion observations of interstellar comet 3I/ATLAS with the IRAM 30-m telescope
The Roth et al. paper concerns the spectroscopic detection of deuterium (2H) in organics (methane, CH4) from small body 3I/ATLAS. Solar System deuterium is a sign of the outer System, but of course 3I is not from this System. We suspect, per other papers, that 3I came from an older, colder or further-out place. That’s the point of studying interstellar comets- what do they say of other systems?
The other Roth et al. paper came from the same JWST observations. Isotopes aside, the activity of 3I ramps up and down as the comet approached the Sun, warmed up, and now is cooling back down again. Comets (e. g., 67P/Churyumov-Gerasimenko) have multiple possible activity mechanisms- which one(s) actually produces their comas is still a matter of debate (even after the Rosetta mission). Each additional comet is another puzzle piece; JW sure comes in handy for ‘small pieces’.
Biver et al. did not use JW, but a radio telescope. Like JW, there are bands where many interesting comet molecules emit their spectral lines. Their radio telescope detected (…and failed to detect) certain volatiles known to be in comets. Like JW, we see what gas emissions do or do not contribute (somehow) to comet activity.
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