Curtsinger/National Geographic/Getty
Earth may have a pair of “ghost moons”, translucent clouds of dust that orbit along with our moon. These clouds, which could be up to 100,000 kilometres across, were predicted in 1951, and new pictures seem to show they exist.
The Earth-moon system has a set of five gravitational balance points, where the gravitational forces from Earth and the moon balance out. At these spots, called Lagrange points, objects can get caught, never being pulled down to Earth or the moon. …