Miles of air cover Earth. The boundary between Earth's atmosphere and outer space, the Kármán line, is about 62 miles (100 kilometers) above the planet's surface. However, about 99.9% of the mass of Earth's atmosphere lies below a height of 30 miles (48 km), according to Anthony Broccoli, a professor of atmospheric science at Rutgers University.
Air is lighter than our bodies, but all those miles of air in the atmosphere amount to a lot of weight. "The total mass of Earth's atmosphere is 5.1 billion billion kilograms, or 11.24 billion billion pounds," Broccoli told Live Science. When it comes to a cylindrical column of air that is 1 foot (0.3 meters) in diameter, "its mass is 1,663 pounds [754 kilograms]," he said.
