While the Moon has always been a source of mystery for people across the world, a new observation has raised the curiosity in astronomy circles even further: Is the Moon drifting away from Earth?
On several occasions during the last decade, scientists have fired laser beams at reflector panels placed about 240,000 miles (385,000 kilometers) away from Earth, on the Moon. By measuring how long it takes laser light to return to Earth — about 2.5 seconds on average — researchers calculate the distance between Earth laser stations and Moon reflectors.
The signals they received back this time indicate that the Earth and Moon are slowly drifting apart at the rate at which fingernails grow or 1.5 inches (3.8 centimeters) per year. This widening gap is the result of gravitational interactions between the two bodies.