Not really, and the scenario has some other problems too[1]. But all sorts of books have fantastic premises, just look at Lord of the Rings! I can accept an awful lot of improbability in a book's setup as long as the plot given that premise makes enough sense. In Seveneves it did so I was happy.
[1]http://hopefullyintersting.blogspot.com/2015/06/seveneves-an...