One of the inevitable problems with writing science fiction is that it's actually quite easy to predict the future and be wrong. Science fiction is full of errors and anachronisms: breathable air on Mars, dinosaurs on Venus, space ships crossing the gulf between stars based on calculations made with a slide rule, or as per my posting on a moon ship whose computer is
filled with vacuum tubes.
However, every once in a great while the balance falls in the other direction. I'm currently reading
Crashing Suns, a collection of Edmond Hamilton science fiction stories that were originally published in the late 1920s. My version, published in 1965, contains the following apologetic note from editor Donald A. Wollheim regarding the various references to our solar system being governed by The League of Eight Worlds:
...the astute reader will also note that in those year the Solar System had only eight planets, Pluto not yet having been discovered.
Ha, well, good news. Thanks to the idiosyncratic 2006 decision by the International Astronomical Union to strip Pluto of its planetary qualifications, if they decide to do another edition they can leave that part out.