Apollo 17 and the Moon

摘要: Apollo 17 was not the last flight of humans to Moon. More lunar exploration and even settlement will occur, baring future stagnation or disappearance our civilization. Exploration scientific investigations in earth sciences are rarely complete, particularly for studies related a specific field site. A long hiatus between may but other forms investigation, directly indirectly related, continue. 17's study Valley Taurus-Littrow on Moon 1972 subsequent examination its significance understanding origin evolution that small planet own constitute good example these facts life. As third specifically “science” missions twentieth century, actually became landing Program September 1970 rather than 11 December when mission reached Taurus-Littrow. The National Aeronautics Space Administration (NASA) President Richard M. Nixon, with acquiescence Congress, had concluded no further planned amortization American taxpayer's investment deep space would be undertaken. The scientists increasingly interested an unnamed, 2300-m deep, 50-km valley, radial 740-km diameter circular basin, Serenitatis, cut through Taurus Mountain ring near crater Littrow. This “Taurus-Littrow,” however, favorite operational planners. In spite pinpoint accuracy they demonstrated all previous since 11, narrow mountainous approach, high valley walls gave planners pause. Their legitimate concerns were compounded by relatively short time, only 14 minutes, navigational updates after acquisition communications from module, Challenger, as orbit before carried it around farside. Initially, trajectory calculations indicated three-sigma errors, normal extremely conservative planning limit, might result hitting side northern mountain wall. Gradually, refinements techniques inevitable synergistic give take so characterized interactions narrowed errors about 1 km, limit where agreed could selected Thus, late February 1972, 9 months launch, approved site 17. The offered four major benefits site, taken context final test then current hypotheses First, photogeologic analysis provided access three-dimensional window into created Serenitatis large basin-forming event, now well established giant impact asteroid comet. Second, units mare basalt older nonmare rocks within easy reach roving vehicle traverses. Third, mantle dark, possibly young volcanic debris partially covered region portions craters range depths penetrated this underlying basalt. And, fourth, lies 600 km north 200 km east 15 sample areas, respectively, adding significantly coverage Moon's nearside. Due foreknowledge series, selection contentious issue among Impact cratering, subjects informers enquiries discussed. Keywords: Apollo 17; Moon; mission; impact cratering; origin; Lunar evolution; Lunar craters; Magma Ocean; cratered highlands; basins; geologic events; implications