r***o 发帖数: 1285 | 1 Explanation: Like a target ring bull's-eye, the Mare Orientale is one of the
most striking large scale lunar features. Located on the Moon's extreme
western edge, this impact basin is unfortunately difficult to see from an
earthbound perspective. It is over 3 billion years old, about 600 miles
across and was formed by the impact of an asteroid sized object. The
collision caused ripples in the lunar crust resulting in the three concentric
circular features visible in this 1967 photograph made by |
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