TV network's souvenir broadcast about moon (10)
I believe the answer is:
eurovision
'tv network's' is the definition.
(I've seen this before)
'souvenir broadcast about moon' is the wordplay.
'broadcast' is an anagram indicator (letters scattered or cast around).
'about' indicates putting letters inside.
'moon' becomes 'Io' (moon of Jupiter).
'souvenir' is an anagram of 'eurovisn'.
'eurovisn' placed around 'io' is 'EUROVISION'.
(Other definitions for eurovision that I've seen before include "contest?" , "TV network" .)