In his tirade against the false teachers, Jude employs the phrase asteres planetai (pronounced as-TER-es pla-NAY-tie), or "wandering stars" (NIV). This is interesting because the planets ("wanderers") of our solar system do not move in synchrony with the most obvious celestial bodies of the night sky, the stars. Today we make an astronomical distinction between planets and stars. Perhaps wandering stars were comets. This may even be an allusion here to the fallen angels.
One way to translate the asters planetai is "stars out of their orbits." How appropriate! The suggestion is that these false teachers are not merely eccentric; they have thrown off all propriety and all restraint. They are truly doing their own thing. They have lost connection with the center.
The little letter of Jude contains a surprising number of memorable phrases -- in English as well as in the original Greek.