As any science fiction reader worth their salt will know already, Nightfall (the original short story by Asimov) is a seminal work in the canon of the genre. This is an adaptation of the original story into a novel.
I am not a fan of works with more than one author (though I have already included a couple, just to show that there are always exceptions in life to any rule) and especially works in later life by a luminary of the genre with a younger co-author (or worse a progeny of the author). These are usually to be avoided.
However in this case Silverberg is a luminary in his own right and the end product is a worthy addition to my bookshelf.