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) in the region has dramatically changed, as did the geothermal activity at Craters of the Moon. The geysers at Wairakei Geyser Valley totally disappeared, but the heat output at Craters of the Moon increased. A lot of hydrothermal eruptions occurred, which formed the craters. In 1950, the total heat output at Craters of the Moon was about 40 MW (megawatts). By 1958, it had increased to about 90 MW. In 1964 it was 420 MW. After 1964 the output declined to about 220 MW in 1979. The most recent estimate being about 200 MW in 2000. Heat output from the