This is Asimov’s first book, and not his best. Its set on an Earth which is radioactive (possibly because of a global nuclear war as supposed in the book, or perhaps because of events described in Robots and Empire). There is a galactic empire at this point, and overall humans have forgotten that they originated on Earth.
(I find that a little hard to believe by the way. Whilst it is true that we have lost historical records from thousands of years ago, we do have some and archeology has constructed at least a partial history for humanity. Additionally, we now have pretty solid record keeping as a society, and it is left unexplained where all those records might have gone. Finally, there is no mention of techniques like carbon dating, which presumably could have been used to prove that Earth is indeed the original planet.)
I did like the general gist of the book, although the conclusion was unsatisfying as well. Overall, not Asimov’s best work.
[award: nominee hugo 1951]