1. INTERPLANETARY MATTER ON THE MOON V.V.Shevchenko Sternberg Astronomical Institute, Moscow University THE SECOND MOSCOW SOLAR SYSTEM SYMPOSIUM MOONS OF PLANETS MOSCOW 2011 IKI RAS

2. Neutron flux measurements of the Moon’s south polar region from the Lunar Exploration Neutron Detector (LEND) on the Lunar Reconnaissance Orbiter (LRO) spacecraft were used for hydrogen mapping of the south pole area. LRO/LEND

3. The final value corresponds to a water (as ice) content of ~4% by weight (Mitrofanov et al., 2010), which is in good agreement with independent estimates of the water content associated with the LCROSS Centaur impact site.

4. The maximum total water vapor and water ice within the LCROSS instrument field of view was 155 kilograms. Given the estimated total excavated mass of regolith that reached sunlight, and hence was observable, the concentration of water ice in the regolith at the LCROSS impact site is estimated to be 5.6 % by mass.

5. In addition to water, spectral bands of a number of other volatile compounds were observed, including light hydrocarbons, sulfur-bearing species, and carbon dioxide (H 2 S/H 2 O, NH 3 /H 2 O, SO 2 /H 2 O, and CO/H 2 O). Of interest is the indication from this preliminary analyses that some volatiles other than water are considerably more abundant (some by orders of magnitude) than the ratios found in comets, in the interstellar medium, or predicted from gas-gas reactions in the protoplanetary disk (Colaprete et al., 2011).

6. LRO/LCROSS IMPACT MISSION: crater with diameter ~ 28 m has total water abundance about 155 kg (A. Colaprete et al., 2011)

7. COLD TRAPS IN CRATER CABEUS (T < 110 K) Sternberg data on the base of LRO/LOLA measurements H, km. Total area of the cold trap in crater Cabeus is ~ 530 km 2 So, we can assume that total water abundance in crater Cabeus is ~ 18х10 3 t

8. SWIRLS IN MARE INGENII AS RESULT OF COMET IMPACT

9. “CLOSE LOOPS” MARE INGENIIMARE MARGINIS “OPEN LOOPS” MARE INGENIIMARE MARGINIS

10. Calculations show, that in case of falling on the Moon such comet as a comet Hale-Bopp, in the lunar environment should remain about 0.1 % of its mass. Taking into account a share of presumably remaining substance on everyone 1 км 2 of lunar surfaces should have about 0.5 × 10 5 t of material. It’s real model (Shevcnenko, 1993 – 1999) COMET HALE-BOPP: 1997 NUCLEUS SIZES: 40 – 80 KM NUCLEUS MASS: ~ 3х10 15 KG

11. Huge comets of Hale-Bopp type usually come from Oort Cloud

12. Comet Hale-Bopp has drifted beyond the orbit of Neptune, over 30,7 AU from the Sun. It continues its outward journey on an epic 2,500 year orbit (Szabo et al., 2011) KUIPER BELT European Southern Observatory's 2.2 meter telescope at La Silla Paranal Observatory in Chile

13. IN SCIENCE BY LEVINSON ET AL. (2010) presented numerical simulations show that the Sun captured comets from other stars while it was in its birth cluster. The results imply that a substantial fraction of the Oort Cloud comets, perhaps exceeding 90%, are from the protoplanetary disks of other stars (!!!)

14. So, it may be that LRO/LEND is seeing interstellar substance on the Moon !? LEND