Moons of Mars on the sides of Saturn (later discovered to be its rings), used the anagram "smaismrmilmepoetaleumibunenugttauiras" for "Altissimum planetam tergeminum observavi" ("I have observed the most distant planet to have a triple form"), Johannes Kepler had misinterpreted it to mean "Salve umbistineum geminatum Martia proles" (Hello, furious twins, sons of Mars). Perhaps inspired by Kepler (and quoting Kepler's third law of planetary motion), Jonathan Swift's satire "Gulliver's Travels" (1726) refers to two moons in Part 3, Chapter 3 (the "Voyage to Laputa"), in which Laputa's astronomers are described as having discovered two satellites of Mars orbiting at distances of 3 and
Sword and planet Mars" by Edgar Rice Burroughs originally serialized by "All-Story" in 1912 as "Under the Moons of Mars". The genre predates the mainstream popularity of science fiction proper, and does not necessarily feature any scientific rigor, being instead romantic tales of high adventure. For example, little thought is given to explaining why the environment of the alien planet is compatible with life from Earth, just that it does in order to allow the hero to move about and interact with the natives. Native technology will often break the known laws of physics. The genre tag "sword and planet" is constructed to