The Hayabusa space capsule that landed in Australia in June last year has yielded some interesting results
Six papers have been published as a result of the Hayabusa mission where surface dust was collected from the surface of asteroid Itokawa. Professor Trevor Ireland from the Australian National University has co-authored four of these papers in the Journal of Science on the findings of the Hayabusa mission.
The papers describe the relationship between meteorites and asteroids. Up until now this was considered problematic due to the surface of meteorites being destroyed as they burn up entering the Earth’s atmosphere.
Information obtained from the small grains of Itokawa’s surface show meteorites that land on Earth are indeed related to asteroids seen in space.
Unfortunately, Hayabusa was unable to collect the full asteroid sample due to a software interlock preventing the collection mechanism from firing. However, the Itokawa sample was able to show that the asteroid ‘skin’ had been exposed to solar wind and cosmic rays for less than 10 million years, meaning that the asteroid is considered very young in solar system terms.
According to Professor Ireland, asteroids are ejected from the asteroid belt and have orbits that slowly decay until they fall into the Sun or collide into planets, or otherwise accelerate away when coming to close to other planets.