Does it shed fresh light on astronomy? (3,4)
I believe the answer is:
new moon
'does it shed' is the definition.
I can't judge whether this defines the answer.
'fresh light on astronomy?' is the wordplay.
I cannot quite understand how this works, but
'fresh' could be 'new' (synonyms) and 'new' is found within the answer.
'light' could be 'moon' (moon is a kind of light) and 'moon' is located in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for new moon that I've seen before include "Lunar narrow, waxing crescent" , "Start of month for some" , "heavenly vision" , "Heavenly body, just visible" , "Beginning of first quarter" .)