At the start of one of my all time favourite movies and novel, a sci-fi masterpiece, 2001 A Space Odyssey, the scene is the dawn of man, approximately 3 million years ago when apes where evolving into primitive humans (hominids) One family group of hominids is settling down for the night. One the man-apes looks up to the starry night sky and beholds a large bright shining object, he is fascinated by it. He is the first of his kind to do so. Since that time we could be so real, humans have been intrigued and enthralled by our close celestial sibling we call the moon.
Astronomically speaking the moon is on our door step, its distance being 363,104 km (225,622 miles) from earth. The moon is believed to have been created approx 4.5 billion years ago. At this time it is believed that a Mars size object collided with the primitive earth, resulting in an enormous and massive ejection of material from earth that later formed the moon. The diameter of the Moon is 3,474 km. ( 2,159 miles). It is approximately a 1/4 size of the earth, which in ratio makes the earth – like moon combination the largest in the solar system. The moon is the fifth largest satellite in the solar system.
The Moon is actually moving away from the earth spinning away at the rate of 3.78cm (1.48in) per year. Without the Moon, the Earth could slow down enough to become unstable, but this would take billions of years for any effect to be noticed.