Man who mapped strange moon crater without working (8)
I believe the answer is:
mercator
'man who mapped' is the definition.
(cartographer Gerardus Mercator)
'strange moon crater without working' is the wordplay.
'strange' indicates an anagram.
'without' indicates named letters should be taken away.
'working' becomes 'on' (on can mean working or activated).
'moon'+'crater'='mooncrater'
'mooncrater' with 'on' removed is 'mocrater'.
'mocrater' with letters rearranged gives 'MERCATOR'.
(Other definitions for mercator that I've seen before include "Projectionist" , "was famous for projection" , "Deviser of projection" , "It turns out Mo Carter was an old Flemish cartographer" , "Flemish mapmaker, giving name to a projection" .)