In my post earlier today, I solicited suggestions for the naming of planet-like objects that aren’t in orbit around stars. Recent surveys and theoretical calculations have shown there may be huge numbers in our galaxy, perhaps more than there are stars. This makes sense for a number of reasons: if planets form in binary star systems, the complex interplay of gravity tends to kick at least some of the planets out of the system, leaving them to roam in the frozen interstellar regions. Some also may have formed as single objects, but being even smaller than brown dwarfs won’t emit even the tiny amount of infrared those weird things emit.
These objects are often known as “rogue planets”, which in my mind has two problems: we’ve developed a habit of thinking of planets as orbiting stars (or stellar remnants like neutron stars and white dwarfs), and it’s a two-word name. Admittedly that last one is aesthetic, but think about it this way: “exoplanet” is a nice punchy term, while “extrasolar planet”, while meaning the same thing, lacks that certain je ne sais quoi. (As Fetcher would say, “That’s French!”) Similarly, “rogue planet” sounds vaguely threatening, “orphan planet” would be a little more accurate, but neither of those would account for planet-like objects that never were in orbit around stars.
However, Caleb Scharf suggests “vagabond” as a descriptive one-word name. It suggests “wanderer”, the original etymology of “planet”, is highly descriptive, and can include Jupiter-like objects too small even to be brown dwarfs. In the Benevolent Dictatorship known as Galileo’s Pendulum, I declare his name Good and Right: they shall be “vagabonds” henceforth in all domains under my control.