Edit: Before I give up on this I wonder how could an advanced civilization create conditions on a small planetoid (Ceres sized?) to keep an Earth level breathable atmosphere? It seems like its impossible in nature, but what about artificially? Some handwavium is allowed of course.
Edit: I previously wrote "within" a small planetoid. Apologies. I meant ON a small planetoid.
Original question: How can small planetoids (Charon, Ceres, Dysnomia sized[?]) have, and keep, an atmosphere with breathable gases for any kind of extended period of time?
I realize that their gravity is low and that might be a reason why it couldn't, but are there any conditions under which they could? For example(s):
- Could it be releasing gases of its own from within its core?
- Could the core have a tiny bit of Neutronium in it (don't laugh)?
- Could a comet have hit it and given it the gases?
I am looking for an answer that would exist in nature, but am open to artificial means as well. Thanks.