Casiopeia or Cassiopeia: How To spell?
The word Casiopeia is misspelled against Cassiopeia, a noun meaning "A constellation of the northern hemisphere, situated between Cepheus and Perseus; -- so called in honor of the wife of Cepheus, a fabulous king of Ethiopia."
Cassiopeia has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings ca & iopeia which should not be misspelled with single 'S'
Wrong Spelling:  ca-s-iopeia  Correct Spelling:  ca-ss-iopeia 
Find more incorrect spellings of Cassiopeia to spell right way.