Uses and properties. The spiral shell and bones reflect the essential presence of calcium in all living things. Calcium is a silvery-white, soft metal that tarnishes rapidly in air and reacts with water. Calcium metal is used as a reducing agent in preparing other metals such as thorium and uranium.
The average distance of the Moon from the Earth is 384,400 km (238,900 mi), or 1.28 light-seconds.
The Moon orbits Earth at an average distance of 382,400 kilometers. The lunar month is the 29.53 days it takes to go from one new moon to the next. During the lunar month, the Moon goes through all its phases. You can see the phases drawn in the image below. Just like the Earth, half of the Moon is lit by the Sun while the other half is in darkness.