Mercury Comes Into Focus

摘要

In January a jubilant NASA mission crew greeted detailed images of nearly 6 million square miles of the surface of Mercury shot by Messenger, the first probe to visit the poorly understood, innermost planet in 33 years. During two days of observation, Messenger surveyed vast stretches of Mercury's surface that had lain in darkness when NASA's Mariner 10 probe made its last flyby in 1975. In October Messenger swept by again and captured most of the remaining uncharted terrain on the solar system's smallest planet (little Pluto is now a "dwarf planet").