Vesta, a massive asteroid over 350 miles across, is the largest known of its kind. With less than a year remaining until Dawn reaches the giant, scientist wait in anticipation. “There’s nothing more exciting than revealing an unexplored alien world,” says Marc Rayman, chief engineer for the Dawn spacecraft. Dawn’s trajectory will bring it into an orbit very close to Vesta’s. Using a slight ion thrust, NASA scientists will gently coerce the spacecraft into a high orbit eventually moving it in to approximately 100 miles high.