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Thales (crater)
Thales is a small crater located in the northeast part of the Moon, just to the west of the larger crater Strabo. To the southeast is the walled plain De La Rue. Thales has a sharp, circular rim that has received little erosion. The lunar surface around Thales has a ray system that extends for over 600 kilometers, and it is consequently mapped as part of the Copernican System.The geologic history of the Moon, 1987, Wilhelms, Don E.; with sections by McCauley, John F.; Trask, Newell J. USGS Professional Paper: 1348. Plate 11: Copernican Systemonline . An area to the north-northwest of the crater is free of rays, however, indicating that the crater may have been formed by a low-angle impact from that direction. The inner wall has some terraces, particularly along the southern side. The sides have a higher albedo than the typical lunar terrain. This crater has been noted for transient lunar phenomena. In 1892, E. E. Barnard Edward Emerson Barnard (December 16, 1857 – Febru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Orbiter 4
Lunar Orbiter 4 was a robotic U.S. spacecraft, part of the Lunar Orbiter program, Lunar Orbiter Program, designed to orbit the Moon, after the three previous orbiters had completed the required needs for Project Apollo, Apollo mapping and site selection. It was given a more general objective, to "perform a broad systematic photographic survey of lunar surface features in order to increase the scientific knowledge of their nature, origin, and processes, and to serve as a basis for selecting sites for more detailed scientific study by subsequent orbital and landing missions". It was also equipped to collect selenodetic, radiation intensity, and micrometeoroid impact data. Mission Summary The spacecraft was placed in a Free-return trajectory, cislunar trajectory and injected into an elliptical near polar high lunar orbit for data acquisition. The orbit was with an inclination of 85.5 degrees and a period of 12 hours. After initial photography on May 11, 1967 problems started occu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
