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| | Where No Man Has Gone Before, Ch13-7 |
 | | Two landing sites had been seriously considered for Apollo 16, the crater Alphonsus, 300 miles (480 kilometers) south of the moon's center, and the region some 340 miles (550 kilometers) east-southeast of the moon's center, north of the ancient crater Descartes. |
 | | The wall of Alphonsus was, some argued, pre-Imbrian highlands material, while dark craters on its floor were thought to consist of relatively young volcanic material that might have originated at great depths. |
 | | 60 Alphonsus remained a strong candidate, but in view of the fact that it would be preferable to have more results from Apollo 14 and 15 before landing there, Descartes was preferred for Apollo 16. |
| www.hq.nasa.gov /office/pao/History/SP-4214/ch13-7.html (1137 words) |
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