Charging and motion of dust
grains near the Moon and
asteroids
N.Borisov
IZMIRAN, Russia
O.E.Berg, H.Wolf, J.Rhee. Lunar soil
movement registered by Apollo 17
cosmic dust experiment.
O’Brien. Review of measurements of dust motion on the Moon during Apollo, Planet Space Sci., 2011.
Lunar surface potential
SIDE results
Freeman and Ibrahim, 1975
Apollo15 subsatellite
results, Anderson et
al., 1972
Electron fluxes at 40,
140, 340, 800, and
2950 eV (LP results,
Lin at al., 1998.
The structure of the double layer behind the Moon (Borisov and Mall, 2002)
The decrease of electron fluxes related to Maxwellian core distribution ~ Exp [e Ф/T]
Formation of strong local electric
fields in the shadow
•
•
Electric charge on a given dust grain
on the surface is several orders of
magnitude less than the equilibrium
charge on the same grain above the
surface in the DL.
Very strong electric fields (E > 100
V/cm) are required to overcome the
gravity of the Moon.
Usw
Vi
dQ

dt
 J ( )
Charging and motion of
dust grains near the
terminator of the moon
(Borisov and Mall, 2006)
Laboratory experiments.
Wang et al. Planetary Space Sci., 2011.
Russian landers of the forthcoming Lunar
missions: Luna-Resourse and Luna-Globe
The Luna-Resourse
(Chandrayaan 2)
project is developing
according to RussianIndian agreement.
It will consist of an
Indian Orbiter and a
Russian Lander that
will carry a small
Indian rover.
The Russia Luna-Globe
project includes a
Lunar Orbiter and a
Lunar Lander.
•
The lunar dust monitor
(PmL) is designed to study
temporal variations of two
expected sources of dust
in the lunar environment:
charged grains lofted by
strong local electric fields
and ejecta production due
to bombardment by
micrometeorites. This
instrument is included into
the payload of landers of
the forthcoming Lunar
missions: Luna-Resourse
and
Luna-Globe.Impact sensor
will measure pulses of
charged grains.
Electrostatic field sensors
will measure electric
potentials at the heights 20
cm and 90 cm and electric
charges
lunar dust monitor
(DML)
 1014 kg * m / s
Influence of local magnetic fields on
dust charging
Mitchell et al., 2008
Theory in two limiting cases:
1. Strong large-scale magnetic anomaly
1 D case (Borisov and Mall, 2003).
Strong non-monotonic variations of the electric
potential above the anomaly are predicted
2. Rather weak and small magnetic anomaly :
nonmagnetized ions and magnetized electrons
i  LM . A  e
Dust motion near asteroids
Asteroid Eros enhanced view
(NEAR-Shoemaker mission)
Details of the surface