The first dust grains ever retrieved from the surface of an asteroid now confirm that these minor planets are constantly shaped by a continuous barrage of high-speed microscopic impacts, scientists find.
The Japanese asteroid probe Hayabusa succeeded in returning more than 1,500 grains of dust from the asteroid 25143 Itokawa when it parachuted into the Australian outback in June 2010.
Already, the samples from this 550 meter rubble pile have helped solve the longstanding mystery of where most meteorites striking our planet come from. To uncover still more details about asteroids, scientists analyzed the size, mineralogy, shape and geochemistry of five dust grains recovered by Hayabusa. (MSNBC)