Moon

The Moon is a ball of rock that orbits the Earth and is the Earth’s only natural satellite. It is 3,456km in diameter and orbits the Earth at a distance of 382,400km away. A complete orbit takes 27 days and 7 hours, during which time the Moon itself also rotates once on its own axis. This means that we always see the same side of the Moon from here on Earth. Because the Earth is also in orbit around the Sun during this time, the actual length of a lunar month, the complete cycle of lunar phases, takes 29 days and 12 hours. These lunar phases are the different stages that we see of the Moon. In reality, we are looking at an increasing and decreasing amount of the daylight side of the Moon, since, like the Earth, the Moon has periods of daylight and darkness with half of the Moon in darkness and half in daylight. It is the Moon’s position in relation to the Sun as it orbits around the Earth that allows us to experience the phases of the Moon. When there is a new Moon, we see the dark (night) side of the Moon. As its position changes, we begin to see a crescent as gradually we see more and more of the daylight side of the Moon. The Moon, up to the time of a full Moon, is called a waxing Moon. After the full Moon, it is said to be waning, as slowly we see less and less until again we can only see the half of the Moon that is in darkness.