23 March 2012 Last updated at 08:15 ET
Giant asteroid Vesta 'resembles planet'
By Paul Rincon Science editor, BBC News website, The Woodlands, Texas
Vesta has been viewed as a massive asteroid, but after studying the surface in detail, scientists are describing it as "transitional".
The Dawn spacecraft has been orbiting Vesta - one of the Solar System's most primitive objects - since July 2011.
They have documented many unexpected features on its battered surface.
Mission scientists presented their latest results at the Lunar and Planetary Science Conference (LPSC) in The Woodlands, Texas.
Dawn's principal investigator, Christopher T Russell, told the meeting that the science team found it hard not to refer to the object as a planet.
He said the rounded asteroid showed evidence of geological processes that characterise rocky worlds like Earth and the Moon....
