Rock of ages

Date:27 October 2012 Tags:, ,

Japan’s Hayabusa spacecraft returned to Earth in 2010 with more than 1 500 pristine dust particles from the asteroid Itokawa. The latest electron microscope analysis shows that the tiny particles – some barely a tenth of a millimetre across – are covered with even tinier craters and microdust particles sometimes melted on to the surface. The findings shed new light on what sorts of particles are bombarding asteroids and how fast they’re travelling. Because asteroids are an intermediate step in a rocky planet’s long cosmic evolution from scattered dust, the samples will help scientists understand how planets form. – Alex Hutchinson