NASA's Dawn spacecraft orbiting the giant asteroid Vesta

An artist's concept shows NASA's Dawn spacecraft orbiting the giant asteroid Vesta. 

The depiction of Vesta is based on images obtained by Dawn's framing cameras. 

NASA announced on Monday that the spacecraft successfully manoeuvred into its closest orbit around the giant asteroid Vesta, beginning a new phase of science observations. 

The spacecraft is now circling Vesta at an altitude averaging about 130 miles (210 km).

Picture: REUTERS/NASA/JPL-Caltech