Here’s an odd thought:
Did Ceres once have an ocean?
The dawn spacecraft has detected minerals that seem to indicate that there was once liquid water on the surface. By “once,” that means “4 billion years ago.” The evidence indicates that there is still substantial water bound upon the surface “rock” of Ceres, with the possibility of meaningful amounts of liquid water still existing under the surface.
But with a surface gravity of only 0.029 g, back when it had an ocean it must have been a bizarre place. That’s far too low a surface gravity (more specifically, far too low of an escape velocity) for Ceres to have retained any sort of atmosphere. Air would quickly just… drift away to space. So the ocean must have been in a constant state of near-boiling, with an astonishing evaporation rate. The atmosphere must have been largely water vapor; the atmosphere would blow away, forming a cometary tail likely to have been pretty impressive. This would have been while planets like Earth were still in the process of being formed, so the entire solar system would likely have been a busy place, with *lots* of giant comet-like objects like Ceres.