NASA's Dawn probe arrived at Ceres today (March 6) at about 7:39 a.m. EST (1239 GMT)

NASA's Dawn probe arrived at Ceres today (March 6) at about 7:39 a.m. EST (1239 GMT), becoming the first spacecraft ever to orbit a dwarf planet. Dawn's observations over the next 16 months should lift the veil on Ceres, which has remained largely mysterious since it was first spotted more than two centuries ago.
"Since its discovery in 1801, Ceres was known as a planet, then an asteroid and later a dwarf planet," Dawn mission director and chief engineer Marc Rayman, who's based at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, said in a statement. "Now, after a journey of 3.1 billion miles (4.9 billion kilometers) and 7.5 years, Dawn calls Ceres 'home.'"