Dark Sanctuary, by Gregory Benford

Dark Sanctuary is one of Benford's early efforts, recently posted.  It's an alien contact story, based on the premise that they have been in our solar system for a long time.  An asteroid prospector discovers them by way of a disabling laser flash, then figures out what they are based on sorting out the implications of their behavior.  It's just a little awkward, especially contrasted with later work, but it's a good read.  I liked it.  Two stars, almost three but not quite.