NASA called the Apollo 11 landing site “Tranquillity Base” because the craft touched down in Mare Tranquillitatis, the Sea of Tranquillity. Six craters form an easy-to-find pattern that leads you to the site. Once you’re in the area, look for the three craters named for the mission astronauts. Because the biggest (Armstrong) is only 2.9 miles (4.6 kilometers) in diameter, you’ll need a large scope to spot it. This region is visible four through 18 days past New Moon. Note that, as with all these areas, shadows will be sharper and detail will be more evident at the beginning and end of that range.