Planetary Science Vision 2050 Workshop 2017 (LPI Contrib. No. 1989) 8066.pdf FUTURE SCIENTIFIC EXPLORATION OF THE MOON: SAMPLE RETURN FROM THE LOWELL CRATER, ORIENTALE BASIN N. Srivastava, Planetary Sciences Division, Physical Research Laboratory, India, email: [email protected] Lunar Science & Exploration - Current State: (and also other planetary bodies) such as Giant Impact The Moon witnessed a string of remote sensing mis- hypothesis [16], Global Magma Ocean hypothesis [17], sions during the past decade due to its immense scien- Impact Cratering - Late Heavy Bombardment (LHB) tific and strategic importance, revealed mostly from [18], and space weathering [19] are outcome of mostly laboratory analysis of Apollo and Luna samples and laboratory studies of the lunar samples. Since, these remote sensing orbiters such as Clementine (NASA; insights are based on samples that were collected with- 1994) & Lunar Prospector (NASA; 1998). The mis- in a limited lunar terrain, our comprehensive under- sions include SMART-1 (ESA; 2003), Kaguya stand about these is somewhat biased [15]. The same is /SELENE (JAXA; 2007), Chandrayaan-1 (ISRO; also evident from the above mentioned surprising out- 2008), Chang´e 1 & 2 (CNSA; 2007 & 2010), Lunar comes from the exhaustive reconnaissance phase of Reconnaissance Orbiter (LRO, NASA; 2009 – still lunar exploration during the past decade and studies of continuing), and Gravity Recovery and Interior Labor- lunar meteorites derived from unknown provenances. atory (GRAIL, NASA; 2011). In addition to these mis- Several earlier questions still remain unanswered sions, Moon Impact Probe (MIP) onboard Chan- and many new questions have erupted regarding origin drayaan-1 and Lunar Crater Observation and Sensing and evolution of the Moon, its current thermal state, Satellite (LCROSS) associated with LRO mission crash nature of its crust and interior, impact cratering pro- landed on the Moon in the year 2008 & 2009 respec- cess, relationship between impact cratering and volcan- tively. Further, Chang´e 3 the 3rd mission of the Chi- ism, and soil maturation process [1-14, 15, 20, 21]. nese Lunar Exploration Program successfully landed Unanimously, the Moon is now much more diverse Yutu rover on the near side of the Moon on 14th Dec. than thought earlier from the study of Apollo and Luna 2013, becoming the first spacecraft to soft-land on the samples. In order to answer these questions and to put Moon since Luna 24 of Soviet Union in 1976. forward another giant leap in lunar and planetary ex- Voluminous high resolution remote sensing data of ploration, it is imperative to obtain rover based and/or various sorts have been generated from these missions manned sample returns from well characterized sites of which are being currently analyzed for deciphering scientific importance, during the next few decades. The surface and subsurface geology of the Moon and com- samples thus obtained will enable us to validate the position and generation of its exosphere. Untill now, findings from remote sensing, refine the existing hy- some of the major discoveries and substantial en- pothesis and build new hypothesis, which would poten- hancements made from earlier understanding of the tially improve our understanding of the Moon as well Moon include evidences for recent volcanism [1-4] and as that of the solar system as a whole. tectonism [5], presence solar wind produced [6] and - endogenous H2O/OH [7], observation of mini- Potential sample return sites: Several studies magnetosphere over magnetic anamoly [8], exposures have addressed to the scientific rationale for lunar of mantle rocks [9], new rock types such as pink spinel sample return in future and potential sampling targets anorthosite [10] and a new type of basalt [11], massive [e.g. 15, 20, 21]. Most of these studies have identified globally distributed blocks of pure crystalline anortho- the largest South Pole Aitken Basin (SPAB) on the far- site [12], un-expectedly numerous exposures of silicic side and the proto-type multi-ring Orientale basin on lithologies [13], and a substantially thinner global lunar the western limb of the Moon as the sites of prime geo- crust than thought earlier [14]. logical importance. Since SPAB is the oldest and the Orientale basin is the youngest multi-ring basin on the Need for sample returns from Moon in future: Moon, radiometric age of both these basins is impera- The Moon is the only planetary body that has been tive to constrain the basin forming epoch and refining sampled through manned (Apollo missions) and robot- of the existing Crater Chronology function widely used ic missions (Luna missions) and from which we have for deriving surface ages of planetary bodies [22]. Fur- meteorites. Studies of these samples have displayed ther, it is now widely accepted from observations and that they can be used to understand planetary - to solar modeling that these colossal impact structures could system scale problems [15]. Popular hypothesis and have exhumed and ejected precious deep-seated rocks major advancements concerning the fundamental pro- along the basin margins [9, 23], which can be sampled cesses related to the origin and evolution of the Moon and brought back for detailed lab investigations. Planetary Science Vision 2050 Workshop 2017 (LPI Contrib. No. 1989) 8066.pdf Sample return from the Lowell crater, Orientale Basin: The Lowell crater (centre lat lon: 13.0°S; 103.4°W, Diameter: 69 km), located in the NW far- side quadrant of the Orientale Basin has emerged as a site of prime geological importance from detailed stud- ies carried out using recently available remote sensing datasets from Kaguya, LRO, and Chandrayaan-1 mis- sions [1-3, 24-27]. The Lowell crater is younger Co- pernican in age (though devoid of rays) and is a host to the ~ 2-10 Ma youngest volcanic flows on the Moon (Figure 1) [1-3] or uniquely developed fresh impact melts [24]. The Lowell crater exhibits conspicuous W- E asymmetries in the morphological make-up of the central peak, crater wall and floor constituents, ejecta distribution, and have potentially sampled undifferenti- ated mantle rocks, rocks from lower crust and anortho- Figure 1. Geological Map of the Lowell Crater [3]. sites (PSA & PAN) [1, 3]. Most of these observed pe- culiarities in the case of the Lowell crater are related its broad geological context. The location of the Lowell References: [1] Srivastava N. et al. (2013) Planet. crater along the mantle extending normal faults consti- & Space Sci., 87, 37-45. [2] Gupta R. P. et al. (2014) tuting the Outer Rook Ring of the Orientale basin [23, Curr. Sci., 107, 3, 454-460. [3] Srivastava N. and Va- 28] favors recent volcanic activity inside it [1-3] and its ratharajan I. (2016) Icarus, 222, 44-56. [4] Braden S. location at the edge of the Orientale transient cavity et al. (2014) Nature Geoscience, 7, 787–791. [5] Wat- provides an opportunity to sample exhumed and eject- ters T. R. et al. (2010) Science, 329, 936 - 940. [6] ed deep seated rocks by the Orientale impact event Pieters C. M. et al. (2009) Science, 326, [23]. Potentially, a manned / rover based sample return doi:10.1126/Science.1178658. [7] Klima R. et al. mission from the Lowell crater would be able to ad- (2013) Nature Geoscience, 6, 737-741. [8] Wiser M. et dress the following important science goals related to al. (2010) Geophys. Res. Let., 37: 015103. [9] Yama- the geology of the Moon: moto S. et al. (2010) Nature Geosciences, 3, 533-536. [10] Pieters C.M. et al. (2011) JGR, 116, E00G08. [11] 1. Recent volcanism with implications to the thermal Ling Z. et al. 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