"The asteroids-are they no more than a rockpile in our Solar System? Or are they actually minor planets in their own right? Will future space explorers make use of them as outposts or find them obstacles to overcome? How many of the moons of the Solar System might in fact be captured asteroids? In this book, Isaac Asimov takes readers on a fascinating tour of the puzzling corners of our space neighborhood that the asteroids call home."-cover.