Meeting with an Asteroid

The Dawn mission is ready for its rendezvous with Vesta, the second-largest asteroid, according to NASA.

According to NASA's Carol Raymond, Vesta will open a window into the history of our solar system and the terrestrial planets.

The spacecraft fires three ion propulsion thrusters continuously,  causing it to catch up with the 359-mile-wide asteroid on July 16 and move initially into a 1,677 mile-high orbit.

From a series of orbits, as low as 200 miles above Vesta, the mission will map the asteroid's surface for a year.

Vesta is thought to be a "protoplanet", which started on the path to becoming a full-fledged rocky (or terrestrial) world like Earth, only to see its ambitions thwarted by Jupiter's disruption of the asteroid belt between Mars and the that planet.

The Dawn team hopes to investigate Vesta for clues to such starter planets and to eyeball a large crater, perhaps 285 miles wide, in the asteroid's south pole, for clues to the object's interior.