Courtesy of http://www.space.com

Bye bye Moon
As you read this, the Moon is moving away from us. Each year, the Moon steals some of Earth’s rotational energy, and uses it to propel itself about 3.8 centimeters higher in its orbit. Researchers say that when it formed, the Moon was about 14,000 miles (22,530 kilometers) from Earth. It’s now more than 280,000 miles, or 450,000 kilometers away

Ocean tug
Tides on Earth are caused mostly by the Moon (the Sun has a smaller effect). Here’s how it works:
The Moon’s gravity pulls on Earth’s oceans. High tide aligns with the Moon as Earth spins underneath. Another high tide occurs on the opposite side of the planet because gravity pulls Earth toward the Moon more than it pulls the water.
At full Moon and new Moon, the Sun, Earth and Moon are lined up, producing the higher than normal tides (called spring tides, for the way they spring up). When the Moon is at first or last quarter, smaller neap tides form. The Moon’s 29.5-day orbit around Earth is not quite circular. When the Moon is closest to Earth (called its perigee), spring tides are even higher, and they’re called perigean spring tides.
All this tugging has another interesting effect: Some of Earth’s rotational energy is stolen by the Moon, causing our planet to slow down by about 1.5 milliseconds every century.

The Moon is a planet?
Our Moon is bigger than Pluto. And at roughly one-fourth the diameter of Earth, some scientists think the Moon is more like a planet. They refer to the Earth-Moon system as a “double planet.“ Pluto and its moon Charon are also called a double-planet system by some.

Sister moons
The Moon is Earth’s only natural satellite. Right? Maybe not. In 1999, scientists found that a 3-mile- (5-kilometer-) wide asteroid may be caught in Earth’s gravitational grip, thereby becoming a satellite of our planet.
Cruithne, as it is called, takes 770 years to complete a horseshoe-shaped orbit around Earth, the scientists say, and it will remain in a suspended state around Earth for at least 5,000 years.

Making of the Moon
The Moon was created when a rock the size of Mars slammed into Earth, shortly after the solar system began forming about 4.5 billion years ago, according to the leading theory.