Szabo, P. S., Poppe, A. R., Biber, H. A., Mutzke, A., Pichler, J., Jäggi, N., Galli, A., Wurz, P., & Aumayr, F. (2022). Deducing Lunar Regolith Porosity From Energetic Neutral Atom Emission. Geophysical Research Letters, 49(21), 1–10. https://doi.org/10.1029/2022GL101232
E134-03 - Forschungsbereich Atomic and Plasma Physics
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Zeitschrift:
Geophysical Research Letters
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ISSN:
0094-8276
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Datum (veröffentlicht):
16-Nov-2022
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Umfang:
10
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Verlag:
American Geophysical Union
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Peer Reviewed:
Ja
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Keywords:
neutral atom emission; simulation; lunar regolith porosity
en
Abstract:
The porosity of the upper layers of regolith is key to the interaction of an airless planetary body
with precipitating radiation, but it remains difficult to characterize. One of the effects that is governed by
regolith properties is Energetic Neutral Atom (ENA) emission in the form of reflected and neutralized solar
wind protons. We simulate this process for the surface of the Moon by implementing a regolith grain stacking
in the ion-solid-interaction software SDTrimSP-3D, finding that proton reflection significantly depends on the
regolith porosity. Via comparison with ENA measurements by Chandrayaan-1, we derive a globally averaged
porosity of the uppermost regolith lay𝐴𝐴ers of 0.85+0.15−0.14. These results indicate a highly porous, fairy-castlelike
nature of the upper lunar regolith, as well as its importance for the interaction with impacting ions. Our simulations further outline the possibility of future regolith studies with ENA measurements, for example, by the BepiColombo mission to Mercury.
