What if the other planets were as close as the moon. -- I wonder if the reason the more distant planets are so much larger is because they are further away from the sun. The planets that are closer to the sun seem to all be much much smaller.
This is the first book in Terry Goodkind's "Sword of Truth" series. It is the basis for the TV show "Legend of the Seeker". There are about 11 books in this series but it is definently worth the length.