More Than 150 Asteroids Have Their Own Moons

Moons are not only for planets. NASA states that more than 150 asteroids are known to have small companion moons. Most asteroids orbit the Sun between Mars and Jupiter, in the main asteroid belt. They range enormously in size, from Vesta, the largest at about 329 miles across, to small asteroids less than 33 feet across. Together they add up to surprisingly little, since NASA says the total mass of all the asteroids combined is less than that of Earth’s Moon. Asteroid moons are more than a curiosity. In 2022, NASA’s DART mission deliberately crashed into Dimorphos, a small moonlet orbiting a larger asteroid, and successfully altered its orbit and physical shape.