Alien found in immense surface (8)
I believe the answer is:
cosmetic
'surface' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'alien found in immense' is the wordplay.
'alien' becomes 'et' (extra terrestrial).
'found in' indicates putting letters inside.
'immense' becomes 'cosmic' (I've seen this in another clue).
'et' going into 'cosmic' is 'COSMETIC'.
Can you help me to learn more?
(Other definitions for cosmetic that I've seen before include "Toiletry to beautify" , "Aesthetic rather than necessary, surgery perhaps" , "Good for appearances only" , "better looks" , "Beauty preparation" .)