LOS ANGELES - After four years sailing through space, the Dawn spacecraft was expected to slip into orbit late yesterday around a giant asteroid to begin a yearlong investigation into the origins of the solar system.
It is the first of two scheduled tour stops for the NASA probe that almost never made it to the launch pad.
Dawn will spend the next several weeks spiraling ever closer to the surface of Vesta, a dry and rocky asteroid about the length of Arizona that is thought to be the source of numerous meteorites found on Earth.
Scientists are eagerly awaiting the first close-up shots of Vesta, expected next month. Until now, it has only been photographed from afar.
Residing in a vast field of rubble between Mars and Jupiter, asteroids are like the Peter Pans of the solar system that never quite grew into full-fledged planets.
That they remain frozen in time is a boon for researchers attempting to reconstruct how Earth and the other planets formed.
Because of its stunted growth, Vesta holds “a record of the earliest history of the solar system,’’ said the mission’s lead scientist Christopher Russell of the University of California, Los Angeles.
After spending a year at Vesta, Dawn will cruise on to an even bigger asteroid, Ceres.