It says in one of the change logs that "emit light" should work now on any object, however I've found that it doesn't work for anything that is not a star.
I've tried big planets, small planets, even a baseball. Setting an object to "emit light" doesn't appear to do anything. When the simulation is saved, closed and then re-opened, the emit light checkbox is unchecked again even though I didn't uncheck it.
I just want a closely orbiting planet to be red hot and therefore emitting just a little light. How can I do this?