Aerial phenomena coming back from areas of ultra-density (4)
I believe the answer is:
ufos
'aerial phenomena' is the definition.
'ufos' can be an answer for 'phenomena' (I have seen 'Mysterious phenomena' mean 'ufos' so perhaps 'phenomena' could also mean 'ufos'). I am unsure of the 'aerial' bit.
'coming back from areas of ultra-density' is the wordplay.
'coming back' says the letters should be written in reverse.
'from' indicates a hidden word.
'sofu' is hidden in the letters of 'areas of ultra density'.
'sofu' in reverse letter order is 'UFOS'.
Can you help me to learn more?
(Other definitions for ufos that I've seen before include "Roswell sightings?" , "Strange aerial objects" , "Mysterious objects in sky" , "Supposed spaceships" , "Potential alien craft" .)