Sulfur Ion Implantations Into Condensed CO2: Implications For Europa

By Keith Cowing
Press Release
December 27, 2022
Filed under , ,
Sulfur Ion Implantations Into Condensed CO2: Implications For Europa
FTIR spectra of condensed CO2 before (black trace) and after (red trace) the implantation of 290 keV S + ions at 20 K. Also shown are the FTIR spectra acquired during control experiments, including an unirradiated CO2:SO2 (6:1) ice mixture at 20 K (blue trace) and a CO2 ice after the implantation of 300 keV He+ ions at 20 K (green trace). The stopping powers of the S+ and He+ ions in the CO2 ice are respectively 4.33 and 9.74 eV Å–1 , while the radiation doses supplied after delivering 1016 ions cm–2 are 325 and 730 eV per CO2 molecule. Note that the spectra of the irradiated ices are difference spectra yielded after the subtraction of the ‘as deposited’ spectra. — astro-ph.EP

The ubiquity of sulfur ions within the Jovian magnetosphere has led to suggestions that the implantation of these ions into the surface of Europa may lead to the formation of SO2.

However, previous studies on the implantation of sulfur ions into H2O ice (the dominant species on the Europan surface) have failed to detect SO2 formation. Other studies concerned with similar implantations into CO2 ice, which is also known to exist on Europa, have offered seemingly conflicting results.

In this letter, we describe the results of a study on the implantation of 290 keV S+ ions into condensed CO2 at 20 and 70 K. Our results demonstrate that SO2 is observed after implantation at 20 K, but not at the Europa-relevant temperature of 70 K. We conclude that this process is likely not a reasonable mechanism for SO2 formation on Europa, and that other mechanisms should be explored instead.

D. V. Mifsud, Z. Kaňuchová, P. Herczku, Z. Juhász, S. T. S. Kovács, G. Lakatos, K. K. Rahul, R. Rácz, B. Sulik, S. Biri, I. Rajta, I. Vajda, S. Ioppolo, R. W. McCullough, N. J. Mason

Comments: Published in Geophysical Research Letters
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Space Physics (
Cite as: arXiv:2212.08947 [astro-ph.EP] (or arXiv:2212.08947v1 [astro-ph.EP] for this version)
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Journal reference: Geophys. Res. Lett., 2022, 49(24), e2022GL100698
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Submission history
From: Duncan V. Mifsud
[v1] Sat, 17 Dec 2022 20:38:11 UTC (472 KB)
Astrobiology, Astrochemstry

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻