Martians as terribly helpful people (10)
I believe the answer is:
samaritans
'helpful people' is the definition.
'Samaritans' can be an answer for 'people' (Samaritan is an example). I am not certain of the 'helpful' bit.
'martians as terribly' is the wordplay.
'terribly' indicates anagramming the letters.
'martians'+'as'='martiansas'
'martiansas' with letters rearranged gives 'SAMARITANS'.
Can you help me to learn more?
(Other definitions for samaritans that I've seen before include "Voluntary organisation to counsel the desperate" , "telephone helpline" .)