Geophysical Research Abstracts Volumi 3, 2001

VARIABLE RADIO EMISSION OF THE MOON AT 25 MM DURING THE
LEONID 2000 METEOR SHOWER

A.A. Berezhnoi (1), E. Bervalds (2), O.B. Khavroshkin (3), G. Ozolins (2), V.V.
Shevchenko (1), V.V. Tsyplakov (3)

(1) SAI, Moscow, Russia; (2) VIRAC, Riga, Latvia; (3) UIEP, Moscow, Russia
Radioseismology of the Moon and planets is based on registration and interpretation
of electromagnetic radiation of seismic origin. The frequency of such
electromagnetic radiation varies from some kHz to the frequency of soft X-ray
radiation. The most probable two models of transformation of mechanical stress into
electromagnetic radiation are: 1) the formation of new microcracks; 2) charges
arising at the peaks of existing cracks drawing under the action of increasing load.
We observed the Moon on November 16 - 18 with the 32 m antenna of the Ventspils
International Radio Astronomy Center at 12.2 GHz. The half-power beamwidth was
3.5 arcminutes. The DSB bandwidth is 2 x 22 MHz and output time constant is 1
sec. The observable lunar region was a seismic active region (30W, 5S). We could
not exactly track the antenna with the velocity of the Moon, an observable region
lagged behind and during 30 minutes of observation cycle the beam draw a near 15
arcminutes long trip on the lunar surface in direction to Mare Serentatis.
During the morning of November 17 we registered significant quasiperiodic
oscillations of the lunar radio emission starting near 1:44 UT. Similar oscillations
were registered on November 18 starting near 2:28 UT. More or less intensive
oscillations (quasiperiods were equal to 1-2 minutes) were received until November
18, 9:30 UT with bottom to peak heights of some K, sometimes up to 10K. The
character of these oscillations is different from atmospheric fluctuations. The time of
observed oscillations does not contradicts with predictions of McNaught about the
Leonid activity on the Moon. Similar oscillations were registered after the Lunar
Prospector impact (July 31, 1999) during observations of the Moon at 13 and 21 cm.
These results can be explained by detection of the lunar radio emission of seismic
origin. The interpretation of quasiperiodic oscillations in terms of Nikolaevsky's
waves is given. Implications of radioseismic method of investigations of the Moon
for determination of the intensity of meteor showers on lunar orbit and for
estimation of the mineral composition of lunar regolith are described.

Berezhnoi, A.A. (1), Klumov B.A.(2), Shevchenko V.V.(1)
(1) Sternberg Astronomical Institute, Moscow, Russia, (2) Institute of Dynamics of
Geospheres, Moscow, Russia

In our previous papers we have found that a significant part of cometary matter is
captured by the Moon after a low-speed collision between a comet and the Moon.
Now we consider the chemical composition of impact vapour formed after a such
collision based on new kinetical model of chemical processes. We have found that
H2O, CO2, and SO2 are main H-, C-, and S-containing species respectively in the
fireball.
The temperature in polar regions near cold traps is suitable for the presence of some
volatile compounds (sulfur, carbon and hydrocarbons) in the regolith. We estimate
an amount of sulfur- and carbon- containing species delivered to lunar polar regions
due to cometary impacts. Our estimations can be checked during conduction of
observations by the SMART-1 spacecraft.

S.G. Pugacheva and V.V. Shevchenko
Sternberg State Astronomical Institute, Universitetskiy pr.13, Moscow, 119899,
Russia pugach@sai.msu.ru Fax: 007-095-932-88-41

The features of the lunar surface, varying in their individual properties, have a
brightness constant in time, and the dynamics of reflected and own radiation is
determined in each case only by the geometry of observing conditions at any given
moment. Therefore, using the known characteristics of the lunar features, we can
determine the standard values of the radiation emitted or reflected by a great number
of particular objects, which form a system of standards in a certain wavelength and
energy-flux range. The space function of the Moon's thermal emission was
constructed by results of the statistical processing of the database 1655 lunar sites in
the vector form. The database contains the brightness characteristics of the emitted
and reflected radiation measured in an IR (10-12 mm) and a visible (0.445 mm) range for
23 Moon's phase angles and 1954 lunar regions. The space function is based on
physical regularities and statistical relationship between the intensity of thermal and
reflected radiation, the geometry of observation and illumination, and the albedo and
microrelief of the lunar surface. An analytic formula of the dependence of radiation
temperature of the lunar surface on the incidence angular parameters make it possible
to calculate the infrared temperature for any geometry of the angular parameters. The
root-mean-square error in the determination of the radiation temperature is +1.5 K.
The computer images were constructed in the form of contour maps of brightness
and temperature, of thermal inertia and other thermal parameters, using the database
of brightness and temperatures values for lunar-surface areas.

THE CRATERING FEATURES OF THE BASIN "SOUTH POLE-AITKEN"

J.Rodionova and E.Kozlova
Sternberg State Astronomical Institute

Morphological features of craters in the South Pole-Aitken are studied. Craters in the
basin are compared to craters located in highland and mare regions. In comparision
studies, the following morphological features were considered: the degree of rim
degradation; the presence of terraces and faults, hills, peaks and ridges, fissures and
chains of small craters, lava on the crater floor; the character of the floor; and the
presence of ray systems. In the basin 3.8 million sq. km in area, 1538 craters of 10
km in diameter or larger are found. Craters in the South Pole-Aitken are found to be
less degraded than those in the mare region. Additionaly, terraces on the inner slopes
of craters in the basin are less degraded, and more faults are observed in the craters
in the highland region. The craters in the three regions studed are similar in the
presence of peaks and hills, while the density of craters with fissures and chains of
small craters on the floor are greater in the mare!
region. No craters with ray systems are found in the basin. The South Pole Aitken
Basin is assumed to have formed late in the period of heavy bombardment. The
morphology of craters in the mare region is found to differ drastically from those in
the basin and the highland region. A low crater density and the abundance of crater-ruins
and craters with faults in the mare region are due to lava flooding of ancient
depressions during the period of basaltic volcanism and the destruction of the
majority of craters formed in the preceding heavy bombardment period. The mare
regions differs in the densities of craters with fissures and chains of small craters,
peaks and lavas on the floor. We attribute these distinctions to the difference in
endogenic processes that proceeded in the considered regions. The endogenic
processes should reveal themselves more often in the mare regions because the lunar
crust here is much thinner than in the highland regions.

LUNAR RESOURCES FOR RESCUE OF MANKIND IN XXI CENTURY

V.V.Shevchenko
Sternberg State Astronomical Institute, Moscow University, Moscow, Russia
shev@sai.msu.ru

In results of many ecological investigations it has been found that the permissible
level of the energy production inside Earth's environment is about 0.1% of solar
energy received by Earth's surface. The value is about 90 TW (90 x 10 12 Watt). On
the other hand, the general estimation shows that the total energy use (and
production, accordingly) in the world is about 16 TW in the end of 2000. This value
will increase by factor of two (about 34 TW) to the year 2050. If the tendency will
be preserved the total energy production in the world will approach to 98 TW to the
year 2100. It means the permissible level of the energy production inside Earth's
environment will be exceeded. But it is obviously that the processes destroying
Earth's environment in global scale will begin before it - after middle of century.
Hence, the first result of the practical actions for rescue of the Earth's environment
must be obtained not late than in 2020 - 2030. It means that general decisions must
be approved now or in the beginning of the new century. The only way to resolve
this problem consists in the use of extraterrestrial resources. The nearest available
body - source of space resources is the Moon. The most known now space energy
resource is lunar helium-3. Very likely, the lunar environment contains new resource
possibilities unknown now. So, the lunar research space programs must have priority
not only in fundamental planetary science, but in practical purposes too.

Department of Lunar and Planetary Research

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