So, looks like the first alien moon to be discovered is a gas giant orbiting a really, really big gas giant.
Or maybe that’s not so surprising, since I guess we still have an easier time finding gas giants of all kinds rather than smaller planets and moons.
Astronomers have pinpointed what appears to be the first moon detected outside our solar system, a large gaseous world the size of Neptune that is unlike any other known moon and orbits a gas planet much more massive than Jupiter.
Given this, doesn’t it sort of seem like one might call this a two-planet binary sort of thing, rather than a planet with a moon? Do we already have a term for binary planets? Seems like that would apply here.
Pretty neat no matter what you call it.