What Used to Be Science Fiction

One of my favorite classic science fiction novels is When World's Collide (1933).  The premise was wild in 1933.  A Neptune-sized planet with an Earth-sized satellite is entering our solar system with a near-miss likely.  As the satellite becomes more obviously not just Earth-sized by Earth-like coming out of a deep freeze, a small group of Anglosphere scientists prepare to swap worlds.  It appears that the near-miss is going to leave the satellite in our orbit and the big visitor will take Earth with it.  (The orbital mechanics of this are not explained and I am skeptical that this could even happen without a collision.)

The time is 1930s.  The technological development is implausible.  They rely on metal expelled from the core during the first pass of the big intruder tidally shaking Earth to its core to make rocket engines.  (The development of de Laval nozzles with perforations to allow fuel cooling of the engine was not yet known.)

It is a great story with many interesting twists.  The 1951 movie version is awful.  These extrasolar intruders, what we now call "rogue planets," were not even in the realm of theory back then.  The discovery of such rogues has been a great surprise.

03/04/25 Futurism details the James Webb Observatory's discovery of a 13 Jupiter mass rogue "just 20 light-years away."  What else is out there?  Let's keep our eyes open.