On May 31st, the asteroid 1998 QE2 passed within six million miles of Earth. A few weeks ago, we got a peek at some of the radar images of this unusual binary asteroid, and now additional radar images let us watch its orbiting moon.

These images were obtained by the Deep Space Network antenna at Goldstone, Calif., on June 1st. 1998 QE2 is one of the slowest (rotation-wise) and largest binary asteroids that we've yet observed. The asteroid itself is roughly 600 meters wide and its satellite, which is in synchronous rotation with QE2, is just 6.4 kilometers wide orbits at a maximum distance of 6.4 kilometers from the primary body. Its most recent pass is the closest approach the asteroid will make to Earth for at least the next 200 years.

Radar Movies Highlight Asteroid 1998 QE2 and Its Moon [NASA via Geekosystem]