Size diameters (a,b,c):572.6 km × 557.2 km × 446.4 km
Semi-major axis: 2.36151 AU
4 Vesta is the second most massive body in the main asteroid belt, accounting for almost nine percent of the total mass of all asteroids. Only dwarf planet Ceres is more massive in that region of rocky debris between Mars and Jupiter. NASA’s Dawn spacecraft circled Vesta from July 16, 2011 until Sept. 5, 2012, when it departed and began its journey to dwarf planet Ceres.