Regolith (from ancient Greek ῥῆγος - blanket and ancient Greek λίθος - stone) is residual soil, which is the product of space weathering of the rock in place [3] .
Currently, this term is most often called the surface layer of loose lunar soil .
Content
Term History
The term regolith was first used by the American geologist G. P. Merril [4] in 1897 . He gave him the following definition [5] :
Regolith - all surface friable formations representing the upper layers of the earth's surface: humus soils , alluvium , weathering products of the rocks, what laterite , aeolian deposits , slope debris , glacial deposits , etc., are.
The modern term regolith is most often applied to the lunar soil , meaning [6]
uncemented product of crushing and redeposition of lunar rocks, a continuous cover covering the surface of the moon. Regolith consists of fragments of lunar rocks and minerals ranging in size from dust particles up to several meters in diameter, glass, lithified breccias , fragments of meteorites, etc.
The term also applies to materials covering the surfaces of other small, atmospheric-free planets and satellites (for example, Mercury , Deimos ), as well as asteroids . Regolith occurs as a result of crushing, mixing and sintering of lunar rocks during the fall of meteorites and micrometeorites in a vacuum and in no way attenuated cosmic radiation. By radioisotopes, it was found that some fragments on the surface of the regolith were in the same place for tens and hundreds of millions of years.
Composition of the lunar regolith
Non-layered, loose, various-grained debris-dust layer, reaching a thickness of several tens of meters. It consists of fragments of igneous rocks, minerals, glass, meteorites and breccias of shock-explosive origin, cemented by glass [7] .
By particle size, it belongs to silty sands (the bulk of the particles have a size of 0.03–1 mm). Color is dark gray to black, with inclusions of large particles having a mirror shine. Particles of the soil have a high slip resistance due to the absence of an oxide film on their surface and high electrification. In addition, lunar dust rises easily from shock effects and adheres well to the surface of solids, which caused a lot of inconvenience to participants in Apollo expeditions. According to Armstrong, Aldrin, and Professor V. F. Scott [8] , regolith in the earth's atmosphere has a characteristic smell of burning and shot caps .
A. P. Vinogradov distinguishes two types of particles in the regolith: angular, similar to the just fragmented rock, and the prevailing rounded particles with traces of melting and sintering. Many of them are vitrified and look like glass and metal droplets. According to the mineral composition of the regolith, it was established that the lunar seas are composed mainly of basalts , and among the continental rocks anorthosites and their varieties prevail. For regolith of both types, the presence of metallic iron particles is characteristic.
Lunar Regolith Color
The colors on the moon are mainly determined by variations in the content of iron and titanium. Maritime regions have low reflectivity because they contain relatively high amounts of iron oxide (FeO). Some marine basalts contain an unusually high concentration of titanium oxide (TiO 2 ) in addition to iron oxide, which makes reflectivity even lower. TiO 2 also shifts the color of the seas from red to blue.
Original Text (Eng.)Colors on the Moon are dominated by controlled iron and titanium content. The mare regions have a low reflectance because they contain relatively high amounts of iron oxide (FeO). Some mare basalts contain unusually high amounts of titanium oxide (TiO 2 ) in addition to iron oxide, making for even lower reflectance. TiO 2 also shifts from red to blue.- [9]
Neil Armstrong on the color of the lunar soil [10] [11] :
When you look at the ground near or in your hand, you find that it is actually coal-gray, and we especially could not find anything different from this color.
Original Text (Eng.)If you look at it, you can’t find it.
The composition of the main rocks of the lunar regolith
The composition of the main rocks of the lunar regolith [13]
| Title | Class | Formula |
|---|---|---|
| Ilmenite | Titanium Iron | FeTiO 3 |
| Olivine | Iron Magnesium Silicate | (Mg, Fe) 2 [SiO 4 ] |
| Anortitis | Calcium Aluminosilicate | Ca [Al 2 Si 2 O 8 ] |
| Pyroxene | Alkali silicates | R 2 [Si 2 O 6 ], where R is Na, Ca |
The elemental composition of the lunar regolith (in%)
| Element | Sea regolith | Mainland Regolith | Regolite individual pools |
|---|---|---|---|
| Ca | 7.9 | 10.7 | 7.7 |
| Mg | 5.8 | 4.6 | 6.1 |
| Fe | 13.2 | 4.9 | 3.7 |
| Al | 6.8 | 13.3 | 9.8 |
| Ti | 3.1 | 0 | 0 |
| Si | 20.4 | 21.0 | 21.8 |
| O | 41.3 | 44.6 | 43.3 |
| S | 0.1 | 0.072 | 0.076 |
| K | 0.1 | 0.073 | 0.24 |
| Na | 0.3 | 0.48 | 0.38 |
Shipping Regolith from the Moon
The first instrumental determination of the density and strength of the surface layer of the regolith was carried out by the Soviet automatic station Luna-13 on December 24–31 1966 [8] .
For the first time lunar soil was delivered to Earth by the crew of the Apollo 11 spacecraft in July 1969 in an amount of 21.7 kg. During the Apollo program’s lunar missions, 382 kg of lunar soil were delivered to Earth [14] . The study of the soil brought by the Apollo was done by Myrtle Bachelder [15] .
The automatic station Luna-16 delivered 101 g of soil on September 24, 1970 (after the Apollo 11 and Apollo 12 expeditions).
" Luna-16 ", " Luna-20 " and " Luna-24 " delivered soil from three areas of the moon: the Sea of Plenty , the mainland region near the Amegino crater and the Sea of Crises in the amount of 324 g, and it was transferred to the GEOKHI RAS for research and storage [16] [17] .
Since 1969, the international conferences on the lunar soil. The first one was called “Apollo Conference”, then, when the Luna-16 samples appeared, the conferences were called the “Lunar Science Conference”, and since 1978 they are called the “Lunar and Planetary Science Conference” [18] . A summary of references to papers on the lunar soil contains more than 3,700 scientific papers [19] [20] . Among them, for example, is the work of Chinese researchers [21] [22] .
See also
- Geology of the Moon
- Moon
- Cosmic weathering
- Moon dust argument
- Helium-3
Notes
- ↑ NASA. Lunar Core Photographs of Sample 10005 .
- THE "THE APOLLO 11 DRIVE TUBES", Dissection and description by Judith H. Allton Undec . NASA (1978).
- ↑ Tomkeev S. I. Regolith - regolith // Petrological English-Russian explanatory dictionary. T. 2. M .: Mir, 1986. p. 157.
- GP Merril GP A treatise on rocks, rock weathering and soils. New York: Macmillan P. 299.
- ↑ Cit. Levinson-Lessing F. Yu. , Struve E. A. Petrographic Dictionary. L.; M .: Geol-Intelligence. Izv-in, 1932. S. 328.
- ↑ Regolith // Petrographic Dictionary / ed. V. P. Petrov, O. A. Bogatikov, R. P. Petrov . M .: Nedra, 1981. C. 351.
- ↑ Green, 2017 .
- ↑ 1 2 I. I. Cherkasov, V. V. Shvarev. Ground of the Moon. M. "Science", 1975.
- ↑ Color of the Moon. NASA official website . 2010-10-10.
- ↑ BBC. Neil Armstrong Interview with Patrick Moore (1970).
- ↑ Telegraph Media Group Limited. Sir Patrick Moore interviews Neil Armstrong in 1970 .
- ↑ The Green Boulder at Station 6a. Apollo Lunar Surface Journal. NASA (1995) .
- ↑ Astronautics. The composition of the main rocks of the lunar regolith.
- ↑ Astromaterials Curation at NASA JSC .
- ↑ Catalog of lunar samples on the website of the Lunar and Planetary Institute. Houston .
- ↑ M. A. Nazarov // Moon Rocks. GEOKHI RAS. 1999 (?) .
- ↑ Moon Ground Archival copy of October 3, 2009 on the Wayback Machine .
- ↑ Archive of conference annotations from 1971 to 2017 .
- Summary of references to scientific publications on lunar soil. Lunar and Planetary Institute. Houston .
- ↑ Young, 2017 .
- ↑ Wang Daode, Ouyang Ziyuan. A preliminary study on the chemical composition of the Apollo 17 high-Ti mare basalt (cn) // Geochimica. - www.cnki.com.cn, 1981. - April.
- ↑ Li Wenzhong, Yang Suizi, Xu Yun, Wang Daode, Cao Jianqiu, Hou Wei. Petrographic and mineralogy studies on Apollo-17 mare basalt // Geochimica. - www.cnki.com.cn, 1980. - March.
Literature
- Shkuratov Yu. G. The moon is far and near . - Kharkov: Kharkov nat. University. V.N. Karazin, 2006. - 182 p. - ISBN 966-623-370-3 .
- Slyuta Ye. N. Physical and mechanical properties of lunar soil (Review) // Astronomical Gazette: journal. - 2014. - Vol. 48 , No. 5 . - p . 358-382 . - ISSN 0320-930X . - DOI : 10.7868 / S0320930X14050053 .
- Ivanov A.V., Nazarov M.A. Study of Regolith Samples Delivered by Automatic Stations of the “Luna” Series // Herald: Scientific and Technical Journal of the NPO. S.A. Lavochkin. - 2012. - № 4 (15) . - p . 48-52 . - ISSN 2075-6941 .
- Mokhov A.V. New ultradispersed mineral phases of the lunar regolith according to the data of analytical electron spectroscopy . - M .: IGEM RAS , 2009. - 51 p. Abstract of doctoral dissertation.
- Anthony Young. The Apollo Lunar Samples - 2017. Collection Analysis and Results . - New York: Springer, 2017. - ISBN 9781461461852 .
- Shevchenko V.V. The moon and her observation. - Moscow: Science, 1983. - 192 p.
- Green LM , Zakharov A.V., Borisova T.A. Lunar Dust // Earth and Universe: Journal. - 2017. - № 3 . - p . 3-17 .
- Lunar soil from the Sea of Plenty. Moscow: Science, 1974. 624 p. - a collection of more than 90 works devoted to the study of the regolith, delivered by the automatic station Luna-16 . The physical and mechanical properties of the lunar soil, articles on mineralogical studies and the study of the chemical composition and distribution of rare elements in the regolith are considered.