First asteroid landed on by a NASA craft (4)
I believe the answer is:
eros
'first asteroid landed on by a nasa craft' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for eros that I've seen before include "Orbiter" , "Form of love" , "Cupid's Greek alternative" , "Famous statue in Piccadilly, London" , "Greek name of Cupid" .)