When the Japanese spacecraft Hayabusa [Hi ya Boo sa] visited the near Earth asteroid Itokawa in 2005 it found this 2000 foot by 800 foot elliptical world to have a variety of surface features. Instead of being a solid object like some asteroids, Itokawa is a rubble pile of boulders and pebbles held together by it's tiny gravity. The total volume of pebbles seems to be comparable to the volume of large rocks and boulders which make up Itokawa , however, the depths of the pebbles or their concentration in the center remains unknown. Given this uncertainty, this asteroid appears to be made up of a million times more small particles than larger ones.