With a diameter of 396 kilometers it is the twentieth-largest moon in the Solar System and is the smallest astronomical body that is known to be rounded in shape because of self-gravitation. "The great light of my forty-foot telescope was so useful that on the 17th of September, 1789, I remarked the seventh satellite, then situated at its greatest western elongation." Video+edition Manu S. Lerma Soundtrack: 1972_ Apollo 17 (NASA) Special thanks: To my Beauty Lau h. Cisneros 2013 http://www.youtube.com/watch?v=dNgHwVTfQfg
