by the Dawn team, which had been positioned so they would not bisect any major surface features. Physical characteristics Vesta is the second most massive body in the asteroid belt, although it is only 28% as massive as Ceres, the most massive body. Vesta is however the most massive body that formed in the asteroid belt, as Ceres is believed to have formed between Jupiter and Saturn. Vesta's density is lower than those of the four terrestrial planets but is higher than those of most asteroids, as well as all of the moons in the Solar System except Io. Vesta's surface area is about the same as the land area of Pakistan, Venezuela, Tanzania, or Nigeria; slightly under . It has a differentiated interior. Vesta is only slightly larger () than 2 Pallas () in volume, but is about 25% more massive. Vesta's shape is close to a gravitationally relaxed oblate spheroid, but the large concavity and protrusion at the southern pole (see 'Surface features' below) combined with a mass less than precluded Vesta from automatically being considered a dwarf planet under International Astronomical Union (IAU) Resolution XXVI 5. A 2012 analysis of Vesta's shape and gravity field using data gathered by the Dawn spacecraft has shown that Vesta is currently not in hydrostatic equilibrium. Temperatures on the surface have been estimated to lie between about with the Sun overhead, dropping to about at the winter pole. Typical daytime and nighttime temperatures are and , respectively. This estimate is for 6 May 1996, very close to perihelion, although details vary somewhat with the seasons. Surface features Before the arrival of the Dawn spacecraft, some Vestan surface features had already been resolved using the Hubble Space Telescope and ground-based telescopes (e.g., the Keck Observatory). The arrival of Dawn in July 2011 revealed the complex surface of Vesta in detail. Rheasilvia and Veneneia craters The most prominent of these surface features are two enormous craters, the -wide Rheasilvia crater, centered near the south pole, and the wide Veneneia crater. The Rheasilvia crater is younger and overlies the Veneneia crater. The Dawn science team named the younger, more prominent crater Rheasilvia, after the mother of Romulus and Remus and a mythical vestal virgin. Its width is 95% of the mean diameter of Vesta. The crater is about deep. A central peak rises above the lowest measured part of the crater floor and the