Say your hero is decelerating from relativistic velocities, easing into the Gliese 229 system, and he slows down by slingshotting around one the largest gas giant in the system, named, uh...oh, crap, I need to come up with the name for that gas giant!
Ancient gods' names are good. But the Greeks are all used up, of course, and the Norse gods seem to obvious. And you loaned your copy of Deities & Demigods to your friend and never got it back. (and it was a first printing, before the Lovecraft estate made TSR yank the Cthulu stuff!) You are going to mention this planet, like, twice in your novel, so you don't want to be up all night coming up with a name for it.
Thank Ra for Godchecker! You could call your gas giant Bishamon (Japanese god of good fortune & war), Ukko (Finnish sky god), or Wandjina (Aborigine creation god). There's enough choices from enough cultures in there that all the science fiction writers in the world won't run out of names.
Another problem solved.