Exploration of the Moon invention of the telescope, an increasing number of people began to recognise the Moon as a sphere, though many believed that it was "perfectly smooth". In 1609, Galileo Galilei drew one of the first telescopic drawings of the Moon in his book and noted that it was not smooth but had mountains and craters. Later in the 17th century, Giovanni Battista Riccioli and Francesco Maria Grimaldi drew a map of the Moon and gave many craters the names they still have today. On maps, the dark parts of the Moon's surface were called "maria" (singular "mare") or seas, and the
Craters of the Moon National Monument and Preserve of lava that erupted from the south-east to north-west trending Great Rift volcanic zone, a line of weakness in the Earth's crust. Together with fields from other fissures they make up the Lava Beds of Idaho, which in turn are in the much larger Snake River Plain volcanic province. The Great Rift extends across almost the entire Snake River Plain. Elevation at the visitor center is above sea level. Total average precipitation in the Craters of the Moon area is between per year. Most of this is lost in cracks in the basalt, only to emerge later in springs and