A Chip Off The Old Block?

Not only planets have moons…so do asteroids. The discovery of tiny Dactyl orbiting around the asteroid Ida in 1993 was quite a shock, with more shocks to come because now many examples of asteroids with moons are known and many more are undoubtedly yet to be discovered. One interesting possibility about the moons of asteroids is that because of their circular motion they represent exterrestrial resources that can easily be sent of in a variety of directions and locations with far more flexibility than moving the asteroids themselves. Whatever their ultimate destiny, their origin remains a mystery. Previously the formation of moons around planets was though to involve impacts or possible co-formation from primordeal material. Now recent work shows that the asteroid moons may in fact be formed by gravity and so are not chips-off-the-old-block after all.