The moon, earth’s only permanent satellite, is believed to be 4.5 billion years old. It was probably formed from debris left over after a astronomical body the size of Mars hit the earth. Ocean tides and the slight lengthening of the day is caused by the moon’s gravitational influence. The distance between the earth and the moon, currently equal to 384,402 km, is slowly increasing.
The 4 moons
Waxing gibbous moon
Riders of the moon (short video)