To early astronomers, the dark spots on the moon appeared to be bodies of liquid. Italian astronomer Galileo Galilei in 1609 was the first to observe the moon through a telescope and named the dark patches "maria," Latin for "seas." In 1645 Polish astronomer Johannes Hevelius, known as the founder of lunar topography, charted 250 craters and other formations on the moon. Many of these were later named for philosophers and scientists, such as Tycho Brahe, Nicholas Copernicus, Johannes Kepler, and Plato.
