First observation of a mini-magnetosphere above a lunar magnetic anomaly using energetic neutral atoms
Abstract
The Sub-keV Atom Reflecting Analyzer (SARA) instrument on the Indian Chandrayaan-1 spacecraft has produced for the first time an image of a lunar magnetic anomaly in backscattered hydrogen atoms. The image shows that a partial void of the solar wind, a mini-magnetosphere, is formed above the strong magnetic anomaly near the Crisium antipode. The mini-magnetosphere is 360 km across at the surface and is surrounded by a 300-km-thick region of enhanced plasma flux that results from the solar wind flowing around the mini-magnetosphere. The mini-magnetosphere is visible only in hydrogen atoms with energy exceeding 150 eV. Fluxes with energies below 100 eV do not show corresponding spatial variations. While the high-energy atoms result from the backscattering process, the origin of the low-energy component is puzzling. These observations reveal a new class of objects, mini-magnetospheres, and demonstrate a new observational technique to study airless bodies, imaging in backscattered neutral atoms.
Keywords
Cite
@article{arxiv.1011.4442,
title = {First observation of a mini-magnetosphere above a lunar magnetic anomaly using energetic neutral atoms},
author = {Martin Wieser and Stas Barabash and Yoshifumi Futaana and M Holmström and Anil Bhardwaj and R Sridharan and M. B. Dhanya and Audrey Schaufelberger and Peter Wurz and Kazushi Asamura},
journal= {arXiv preprint arXiv:1011.4442},
year = {2010}
}
Comments
17 pages, 3 figures