The first attempts to reach Mars (1960) and Venus (1961) failed, yet triump followed quickly. Of the nearly 200 solar, lunar, and interplanetary missions depicted on this map, most have been Earth's closest neighbors. As rocketry, navigation, and imaging have become ever more capable and reliable, the planets and many of their moons have been examined in detail. The New Horizons mission to Pluto is under way, as is the MESSENGER mission to Mercury. Others not yet launched, perhaps not yet dreamed, await. --National Geographic