Lunar craters Lunar craters Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, almost all of which were formed by impacts. The word "crater" was adopted from the Greek word for vessel - (Κρατήρ a Greek vessel used to mix wine and water). Galileo built his first telescope in late 1609, and turned it to the Moon for the first time on November 30, 1609. He discovered that, contrary to general opinion at that time, the Moon was not a perfect sphere, but had both mountains and cup-like depressions. These were named craters by Schroeter (1791), extending
Craters of the Moon National Monument and Preserve of open rift cracks in the world, including the deepest known on Earth at . There are excellent examples of almost every variety of basaltic lava, as well as tree molds (cavities left by lava-incinerated trees), lava tubes (a type of cave), and many other volcanic features. Craters of the Moon is in south-central Idaho, midway between Boise and Yellowstone National Park. The lava field reaches southeastward from the Pioneer Mountains. Combined U.S. Highway 20–26–93 cuts through the northwestern part of the monument and provides access to it. However, the rugged landscape of the monument itself remains remote and undeveloped,