Ceres

Ceres is a dwarf planet in the main asteroid belt between Mars and Jupiter. Its comparatively rounded shape distinguishes its self-gravitating structure from many much smaller irregular asteroids; its location and dynamical context distinguish it from a major planet.

The Dawn spacecraft investigated its surface using imaging, spectroscopy and gravity measurements. Water-bearing minerals and bright salt-rich deposits provide evidence of chemical interaction with water. These observations constrain surface and near-surface processes, while any reconstruction of the deeper interior also requires a model; a bright deposit alone is not a complete map of an underground reservoir.^[ref]