Measurements of Physical and Optical Properties of Individual Cosmic and Lunar Dust Grains
Principal Investigator (NASA/MSFC):
Dr. Mian Abbas
Dr. Jim Spann,
Dr. Paul Craven,
Dust grains constitute a major component of matter in the
universe. About half of all elements in the interstellar
medium (ISM) heavier than helium
are in the form of dust. Micron/sub-micron
size cosmic dust grains play an important role in physical and
dynamical processes in the galaxy, the ISM, and the
interplanetary and planetary
environments. Knowledge of the physical, optical, and charging
properties of the cosmic dust provides valuable information
about many issues dealing with the role of dust in astrophysical
Dust in the Interstellar Medium/ Cosmic Dust Cycle:
Dust particles are formed in astrophysical environments by
processes such as stellar outflows and supernovae.
Ejected into the ISM, they lead to the formation of diffuse and
dense molecular clouds of gas and dust. The gas and dust in the
interstellar clouds undergo a variety of complex physical and
chemical evolutionary processes leading to the formation of stars
and planetary systems, forming a cosmic dust cycle.
Dust in the Interplanetary Medium:
The interplanetary dust cloud (IDC) constitutes the dust in the
interplanetary medium extending
from the inner solar system to
the asteroid belt. Zodiacal light is the visible light
scattered by dust particles in
the IDC. Particles in the IDC
spiral towards the Sun (Poynting-Robertson effect) with
lifetimes of ~104to 105 years
and are evaporated or driven out of the solar system. The sunlight
absorbed and re-radiated in the
infrared by the dust dominates
the sky in the 3-70 mm spectral region.
Dust in the Lunar Environment:
The Apollo astronauts found lunar dust
to be unexpectedly high in its
sticking to the suits,
instruments, and the lunar rover. The Lunar Surveyor
spacecraft and the Lunar Ejecta and Meteorite Experiment on
Apollo 17 indicated the presence of transient dust clouds.
A horizon glow over the lunar terminator and high
altitude streamers were observed
by the astronauts on the Apollo
Neil Armstrong on the Moon
The lunar dust phenomena are attributed to the electrostatic charging of the
dust grains by UV photoelectric
emissions on the dayside leading
to positively charged grains.
On the night side, the electron
or ion collisions generally lead
to negatively charged grains,
with electrons dominating the
charging process. Secondary
electron emission induced by
solar wind electrons with
sufficiently high energy may
produce positively charged
grains. Measurements of the
optical and physical properties
of individual lunar
dust grains are required to understand and mitigate the
hazardous effects of the lunar dust phenomena.
SEM images of Apollo 17 dust grains
Measurements on Individual Micron
Size Dust Grains in the Dusty
Plasma Laboratory at Marshall:
The Lab Setup and the EDB
The above photo shows an experimental facility developed at MSFC
that is based on an electrodynamic balance (EDB) for
investigation of the properties of individual micron/submicron
size dust grains in simulated
space environments. A number of
unique experiments have been
conducted at this facility to
investigate several different
properties and processes of
astrophysical interest. These
studies employed dust grains
comprising the analogs of cosmic
dust as well as dust grains
selected from the sample returns
of the Apollo-17 and Luna 24
- First Laboratory measurements of radiation pressure on individual micron-sized dust grains (pdf 200K)
- First Measurements of
rotation and alignment of micron-sized dust grains (pdf 424K)
simulating the rotation
and alignment of interstellar
grains. Theories of rotation and
alignment of dust grains are
expected to provide possible
means for evaluation of the
galactic magnetic fields, and for
investigation of the phenomena of
rotational bursting in the
- Measurements of the photoelectric efficiencies for charging of
the analogs of individual cosmic
(pdf 311K) dust grains and
- Apollo lunar
dust grains (pdf 229K) by UV radiation.
The results are found to be
substantially different from the
only available measurements made
on bulk materials reported in the
- Measurements of the charging
of Apollo lunar dust grains by electron impact (pdf 229K),
charging of lunar dust by the
solar wind plasma.
- Comparison of charging by photoelectric emissions and by
electron impact of Apollo 11, 12, 14, 15, 16, and
17 dust grains collected from different lunar sites.
- Experimental evaluation of the effect of the
lunar temperature cycle (~100
to 400 K) on the dust charging
rates and the equilibrium
- Experiments on
condensation of volatile gases on interstellar type
cryogenically cooled dust
grains for investigations of the
formation and growth of icy
- Measurements of the infrared optical properties in
the middle- and far-infrared
spectral regions (10 to 2500 cm-1)
with the growth of icy mantles.
- Laboratory investigation of the alignment mechanisms of rotation of dust
- Abbas, M. M., D. Tankosic, Spann, J.F., Dube, M.J., and Gaskin, J.A.,
Measurements of Charging of Apollo 17 Lunar Dust Grains by
Electron Impact, STAIF Conference Proceeding, 942-948, 2008.
- Abbas, M. M., D.
Tankosic, P. D. Craven, J. F.
Spann, A. LeClair, and E. A.
West, Lunar dust charging by
Planet. Space Sci. 55, 953-965,
- Abbas, M. M., D.
Tankosic, P. D. Craven, J. F.
Spann, A. LeClair, E. A. West, J.
C. Weingartner, A. G. G. M.
Tielens, J.A. Nuth, R. P. Camata
and P. A. Gerakines, Photoelectric
emission measurements on the
analogs of individual cosmic dust
Journal, Vol. 645. No.1, July 1,
- Abbas, M. M., Craven, P.
D., Spann, J. F., Tankosic, D.,
LeClair, A., Gallagher, D. L.,
West, E.A., Weingartner, J. C.,
Witherow, J. C. and Tielens, A.
G. G. M., Laboratory
Experiments on Rotation and
Alignment of the Analogs of
Interstellar Dust Grains by
Journal, Vol. 614, 781-795, 2004.
- Abbas, M. M., P. D.
Craven, J. F. Spann, W. K.
Witherow, E. A. West, D. L.
Gallagher, M. L. Adrian, G. J.
Fishman, D. Tankosic, A. LeClair,
R. Sheldon, and E. Thomas Jr., Radiation
pressure measurements on
micron-size individual dust
grains, J. Geophys. Res. 108,
- Spann, J. F., M. M.
Abbas, C. C. Venturini, and R. H.
balance for studies of cosmic
dust particles, Physica
Scripta. Vol. T89, 147-153, 2001.