Simplify the following text for a Grade 9 native English-speaking person.
Original: The major charactersâ '' the Sailor Senshi ( literally `` Sailor Soldiers '' ; frequently called `` Sailor Scouts '' in many Western versions ) , teenage girlsâ '' can transform into heroines named for the moon and planets ( Sailor Moon , Sailor Mercury , Sailor Mars , etc. ) .
Simplified: They are named Sailor Mercury , Sailor Venus , Sailor Mars , and Sailor Jupiter .