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 (geothermal site) an “unearthly” atmosphere. The craters are a relatively recent feature of the area and appeared as a result of human activity in the region. The site is Crown Land, administered by the Department of Conservation, with help from the "Craters of the Moon Trust", a volunteer organisation that provides information for visitors and passive vehicle security. In 1859 Ferdinand von Hochstetter, an Austrian geologist who traveled through the area, reported a colossal column of steam from the Karapiti Blowhole (fumarole), observable from about 20 km away. It was difficult to approach because steam vents and springs covered the valley floor