This is science fiction in the tradition of Arthur C. Clarke, indeed when an asteroid appears in a nova-like burst of radiation and sails neatly into an orbit round the Earth and Moon, one is instantly reminded of Rendez-vous with Rama, but this artifact is not alien. The Clarke tradition is to take an Idea then build a story round it; this can lead to novels that really don't have a good story or even much of a story at all, for example, Niven's Ringworld. With Eon, Bear does not suffer this problem; he tells a story that leads straight from extrapolation of the consequences of the Idea he had. It's a clever story and never boring but its one weakness is that it uses several major characters in order to cover all aspects and veiwpoints of the narrative. This splits one's sympathies so that the reader never fully invests in one character's interests - this leaves one too much outside the story, looking in.