A GALACTIC sea otter, or merely an orbiting heap of rubble? The Itokawa asteroid, examined by Japan’s Hayabusa spacecraft, has been called both. The latest analysis has thrown up a more vexing question: how on earth does the rubble stay together?
Named after late rocket scientist Hideo Itokawa, the asteroid is basically a 535-metre-long pile of rubble packed even more loosely than a handful of sand. Some astronomers – who clearly don’t get out enough – claim it looks like a sea otter. Bafflingly, Itokawa appears to be 40 per cent porous, while a handful of sand is only 20…
