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
Banting (crater) moon, which constantly faces Earth because of its tidally locked orbit. This makes Sir Frederick’s crater fairly central, since Mare Serenitatis is so easily viewed. Despite its location, Banting is a very small crater and can be difficult to see. A telescope must be used, and viewing during certain lunar phases is crucial to seeing such small craters, as well. It is recommended that, while it is waxing, the moon be viewed around the time of its first quarter; while it is waning, it should be viewed just before its last quarter. Craters may also be conspicuous during a gibbous