Man's man is moon explorer? (8)
I believe the answer is:
islander
'man's man' is the definition.
(I've seen this in another clue)
'is moon explorer?' is the wordplay.
'moon explorer?' becomes 'lander' (I can't justify this - if you can you should believe this answer much more).
'is'+'lander'='ISLANDER'
Can you help me to learn more?
(Other definitions for islander that I've seen before include "Eg, a Manxman" , "person from Cuba?" , "Native of Bali, perhaps" , "Manxman, maybe," , "Friendly person" .)