umu.sePublications
Change search
ReferencesLink to record
Permanent link

Direct link
Scattering characteristics and imaging of energetic neutral atoms from the Moon in the terrestrial magnetosheath
Umeå University, Faculty of Science and Technology, Department of Physics. Swedish Institute of Space Physics, Kiruna, Sweden.
Show others and affiliations
2016 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 121, no 1, 432-445 p.Article in journal (Refereed) PublishedText
Abstract [en]

We study hydrogen energetic neutral atom (ENA) emissions from the lunar surface, when the Moon is inside the terrestrial magnetosheath. The ENAs are generated by neutralization and backscattering of incident protons of solar wind origin. First, we model the effect of the increased ion temperature in the magnetosheath (>10 times larger than that in the undisturbed solar wind) on the ENA scattering characteristics. Then, we apply these models to ENA measurements by Chandrayaan-1 and simultaneous ion measurements by Kaguya at the Moon, in the magnetosheath. We produce maps of the ENA scattering fraction, covering a region at the lunar near-side that includes mare and highland surfaces and several lunar magnetic anomalies. We see clear signatures of plasma shielding by the magnetic anomalies. The maps are made at different lunar local times, and the results indicate an extended influence and altered morphology of the magnetic anomalies at shallower incidence angles of the magnetosheath protons. The scattering fraction from the unmagnetized regions remains consistent with that in the undisturbed solar wind (10%-20%). Moreover, the observed ENA energy spectra are well reproduced by our temperature-dependent model. We conclude that the ENA scattering process is unchanged in the magnetosheath. Similarly to the undisturbed solar wind case, it is only magnetic anomalies that provide contrast in the ENA maps, not any selenomorphological features such as mare and highland regions.

Place, publisher, year, edition, pages
2016. Vol. 121, no 1, 432-445 p.
Keyword [en]
Moon, energetic neutral atoms, magnetosheath, scattering, regolith, magnetic anomalies
National Category
Fusion, Plasma and Space Physics
Identifiers
URN: urn:nbn:se:umu:diva-118425DOI: 10.1002/2015JA021826ISI: 000371146900031OAI: oai:DiVA.org:umu-118425DiVA: diva2:917365
Available from: 2016-04-06 Created: 2016-03-18 Last updated: 2016-04-06Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Lue, Charles
By organisation
Department of Physics
In the same journal
Journal of Geophysical Research - Space Physics
Fusion, Plasma and Space Physics

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 6 hits
ReferencesLink to record
Permanent link

Direct link