LOS ANGELES - After a nearly eight-year journey, a NASA spacecraft on Friday flawlessly slipped into orbit around Ceres in the first visit to a dwarf planet.

The robotic Dawn craft will circle the dwarf planet for more than a year, exploring its surface and unraveling its mysteries.

"It went exactly the way we expected. Dawn gently, elegantly slid into Ceres' gravitational embrace," said Marc Rayman, chief engineer for the $473 million mission managed by NASA's Jet Propulsion Laboratory in Pasadena.

Ceres is the second and final stop for Dawn, which launched in 2007 on a voyage to the main asteroid belt, a zone between Mars and Jupiter that's littered with rocky leftovers from the formation of the sun and planets 41/2 billion years ago.

Dawn will spend 16 months photographing the icy surface. It previously spent a year at Vesta exploring the asteroid and sending back stunning close-ups of its lumpy surface before cruising onto Ceres, the largest object in the asteroid belt.

The three billion mile trip was made possible by Dawn's ion propulsion engines, which provide gentle yet constant acceleration and are more efficient than conventional thrusters.