Our planet’s proper-noun Moon, the one we call Luna, has been hanging out around Earth for about 4 billion years. A new simulation says that at any moment, Luna is not alone.
University of Helsinki researchers used a massive supercomputer to simulate 10 million tiny asteroids, just a few feet across, passing Earth. Between the gravitational pull of the Sun, Moon and Earth, tens of thousand were captured. As a result of these calculations, which would have taken your home computer six years, they estimate that at any moment Earth is joined by at least one “mini-moon”.
These tiny asteroids can orbit for years, undetected, before being pulled back into a path around the Sun. If we could capture one, imagine what we could discover about the early Solar System!