Nasa spacecraft to attempt sampling asteroid for return to Earth

Asteroid Bennu, as seen from the Osiris-Rex spacecraft (Nasa/Goddard/University of Arizona/CSA/York/MDA via AP)

After almost two years circling an ancient asteroid hundreds of millions of miles away, a Nasa spacecraft will this week attempt to descend to the treacherous, boulder-packed surface and snatch a handful of rubble.

The drama will unfold on Tuesday as the US has its first go at collecting asteroid samples for return to Earth, a feat accomplished only by Japan so far.