In 1776, the moon was a clock, a calendar and a streetlight — and it was 31 feet closer to Earth

A photo showing the moon in a blue sky. On the lower half of the screen, there's an American flag.

After Americans declared independence on July 4, 1776, a waning gibbous moon rose in the night sky. To the people celebrating the birth of a new nation, it would have looked much the same as the moon we see today. But there was one subtle difference: 250 years ago, the moon was about 31 feet (9.4 meters) closer to Earth than it is now.

"The moon is currently drifting away from Earth at a rate of about 3.8 centimeters [1.5 inches] per year, which is coincidentally roughly the same speed at which human fingernails grow," says Seth McGowan, president of the Adirondack Sky Center & Observatory in Tupper Lake, New York.