In the last panel, I think the starman is either intercepting the call or getting a similar one from his home world.
The alien script is the same as the one from DDDD which I
mostly deciphered awhile back. If you map the alien lines back to Japanese, the lossy version of the panel reads:
OCTA: ... O A M? M? M? N? N? T? G? B? R? Y? S? N? D? N? A
OCTA: M? R? S? R? N? Y?
PHONE: G? T? N?
PHONE: T?- T?- T?-
Cross referencing with a
sample of the raw, the lines in the 2nd panel seem nearly identical to the 1st after recovering the lost parts of each kana:
OCTA: ... O A MO MAMA NI NITE GANBARIYA S? N? DA NAA
OCTA: MURI SURU NA YO
PHONE: GOTON
PHONE: TSU- TSU- TSU-
There are still some gaps in the mapping so either there's something about the alien language I still don't understand or Asano made some errors in the encoding (I'm betting on the former though :'))