Whistler Wings and Reflected Particles during Solar Wind Interaction of
Lunar Magnetic Anomalies
Abstract
The planetary magnetic fields in the solar system deflect/reflect solar
wind at bow shocks in front of their magnetospheres, protecting the
planets from direct solar wind bombardment. Indirect evidences suggest
that the sporadic magnetic anomalies on the Moon, i.e., the small-scale
magnetic fields, do the same, protecting the lunar surface below and
even modifying the chemical/optical properties there. It is, however,
still unclear how these anomalies interact with solar wind because of
lack of in-situ observations. Two key remotely-sensed symptoms,
i.e., the lunar reflected ions and the associated ~1Hz
waves, are organized in a particular coordinate system here to diagnose
the solar wind interaction. We show that particles are reflected around
the specular direction above the lunar surface, hinting an
electric-field effect in the reflection, and that whistler wings form,
suggesting a distinct solar wind interaction scenario to that of a giant
planetary field.