Perhaps foundation of the universe cracked by alien (8)
I believe the answer is:
cosmetic
'perhaps foundation' is the definition.
(foundation is an example)
'of the universe cracked by alien' is the wordplay.
'of the universe' becomes 'cosmic' (I've seen this before).
'cracked by' is an insertion indicator (to crack can mean to create a divide in).
'alien' becomes 'et' (extra terrestrial).
'cosmic' going around 'et' is 'COSMETIC'.
(Other definitions for cosmetic that I've seen before include "Designed for appearance' sake" , "Toiletry to beautify" , "With surface effect only" , "Superficial - lipstick, say" , "better looks" .)