Dynamics of solar wind protons reflected by the Moon

Abstract

Solar system bodies that lack a significant atmosphere and significant internal magnetic fields, such as the Moon and asteroids, have been considered as passive absorbers of the solar wind. However, ion observations near the Moon by the SELENE spacecraft show that a fraction of the impacting solar wind protons are reflected by the surface of the Moon. Using new observations of the velocity spectrum of these reflected protons by the SARA experiment on-board the Chandrayaan-1 spacecraft at the Moon, we show by modeling that the reflection of solar wind protons will affect the global plasma environment. These global perturbations of the ion fluxes and the magnetic fields will depend on microscopic properties of the object's reflecting surface. This solar wind reflection process could explain past ion observations at the Moon, and the process should occur universally at all atmosphereless non-magnetized objects.

12 pages, 8 figures

References in corpus (1)

• Extremely high reflection of solar wind protons as neutral hydrogen atoms from regolith in space

Cited by in corpus (7)

• First observation of a mini-magnetosphere above a lunar magnetic anomaly using energetic neutral atoms
• The interaction between the Moon and the solar wind
• A new view on the solar wind interaction with the Moon
• Protons in the near-lunar wake observed by the Sub-keV Atom Reflection Analyzer on board Chandrayaan-1
• Characteristics of proton velocity distribution functions in the near-lunar wake from Chandrayaan-1/SWIM observations
• Laboratory modelling of solar wind interaction with Lunar Magnetic Anomalies
• Activity in the lunar surface: Transient Lunar Phenomena