Refracting telescope focus, results in a non-inverted and upright image. Galileo’s best telescope magnified objects about 30 times. Because of flaws in its design, such as the shape of the lens and the narrow field of view, the images were blurry and distorted. Despite these flaws, the telescope was still good enough for Galileo to explore the sky. The Galilean telescope could view the phases of Venus, and was able to see craters on the Moon and four moons orbiting Jupiter. Parallel rays of light from a distant object (y) would be brought to a focus in the focal plane of the
Craters of the Moon National Monument and Preserve available in the Craters of the Moon Wilderness and the much larger Backcountry Area beyond (added in 2000). Only two trails enter the wilderness area and even those stop after a few miles or kilometers. From there most hikers follow the Great Rift and explore its series of seldom-visited volcanic features. All overnight backcountry hikes require registration with a ranger. No drinking water is available in the backcountry and the dry climate quickly dehydrates hikers. Avoiding summer heat and winter cold are therefore recommended by rangers. Pets, camp fires, and all mechanized vehicles, including bicycles, are not allowed in the