NASA is getting ready for its Dawn spacecraft's encounter with a giant asteroid, set to happen in less than a year, the agency said.

Dawn will conduct a detailed study as it spends a year circling the asteroid Vesta, becoming the first spacecraft to orbit a body in the solar system's asteroid belt, SPACE.com reported Tuesday.

There have been previous missions to asteroids, but scientists say Vesta offers a chance for something special.

"Vesta is going to amaze us," Marc Rayman, Dawn's chief engineer at NASA's Jet Propulsion Laboratory, said.

At 350 miles across, Vesta is the second-largest body in the asteroid belt, containing almost 10 percent of the entire belt's mass. Only the asteroid Ceres, so large it is considered a dwarf planet, is a bigger belt object than Vesta.

"It's a big, rocky, terrestrial-type body -- more likely similar to the moon and Mercury than to the little chips of rocks we've flown by in the past," Rayman said of Vesta.

Scientists expect Dawn's mission will help them understand how planets form.

Astronomers think Vesta was in the process of becoming a full-fledged planet when Jupiter interrupted its growth as the gas giant's gravity stirred up the material in the asteroid belt so objects there could no longer come together and coalesce.

After a year orbiting Vesta, Dawn will move on to take a look at the only asteroid considered even more interesting, the dwarf planet Ceres.