The Moon is the Earth's single satellite that orbits around the planet. It is seen at night and it changes its appearances from a full moon to waning gibious/crescent, waxing gibious/crescent, new moon, first and last quarter. The moon is also famous for the Solar Eclipse when it covers the Sun.
When the 2012 apocalypse occurred on Earth, the moon did not change or get destroyed as it remained in space while the planet got destroyed by three geological natural disasters. When the apocalypse ended, the moon continued to stay in orbit and when time was reset to year one, the moon continued to orbit the newly transformed Earth (which had only Africa and a few continents risen).