My buddy MOATMAI gave me a copy of "The Black Cloud" by world-famous astronomer Fred Hoyle, published in 1957. It's a hard-science SF novel about our solar system moving into a nebula, basically. It's set in the then-future year of 1964. I think it was written at least partially in reaction to George Pal's incredibly soft SF movie, "When Worlds Collide," from 1954. This, in turn, was based on a spectacularly soft SF novel by the same name from the late 1930s.

A clump of tumbled stones lay at the center of a small valley, far out in the arid desert; the remains of an ancient outpost, abandoned since the time of the last men. It was quiet and still, and it seemed all rather peaceful.

And so it was, while the gun turret watched.