First observation of a mini-magnetosphere above a lunar magnetic anomaly using energetic neutral atoms
Article first published online: 6 MAR 2010
Copyright 2010 by the American Geophysical Union.
Geophysical Research Letters
Volume 37, Issue 5, March 2010
How to Cite
2010), First observation of a mini-magnetosphere above a lunar magnetic anomaly using energetic neutral atoms, Geophys. Res. Lett., 37, L05103, doi:10.1029/2009GL041721., , , , , , , , , and (
- Issue published online: 6 MAR 2010
- Article first published online: 6 MAR 2010
- Manuscript Accepted: 19 JAN 2010
- Manuscript Revised: 5 JAN 2010
- Manuscript Received: 10 NOV 2009
- energetic neutral atoms
 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.