Jiggling Asteroid

Shaun Saunders, just sent me a very interesting article concerning the asteroid Itokawa. It seems that the diminutive asteroid (only 1,600 feet ,500 meters, in diameter.) jiggles like jar of mixed nuts! This "jiggling" action, is sorting loose rock particles on its surface by size, causing the smallest grains to sink into depressions. Images, taken by the Japanese Hayabusa spacecraft in 2005, revealed that some areas were coated with fine particles and appeared smooth, while others regions looked bumpy, The regolith (a mix of boulders and gravel), distribution suggests Itokawa has been shaken up in the past, but what might have rattled it is still an open question. One hypothesis is that smaller asteroids occasionally strike Itokawa and shake the space rock up. Because of its diminutive size, even tiny impacts could send Itokawa into a tremor. Another idea is that Itokawa might occasionally fly close enough to the Earth, where our planet’s gravity could jostle it.