Disintegration of remote extraterrestrial rock (6)
I believe the answer is:
meteor
'extraterrestrial rock' is the definition.
(rock flying through space)
'disintegration of remote' is the wordplay.
'disintegration of' indicates anagramming the letters (I've seen 'disintegration' mean this).
'remote' is an anagram of 'METEOR'.
(Other definitions for meteor that I've seen before include "Component of shower" , "Remote sort of heavenly body" , "lump of rock" , "Shooting star" , "streaker?" .)