The planet probably got this name due to its red color; Mars is sometimes referred to as 'the Red Planet'.
A lot of people refer to Mars by it's nickname.
( z1 refer :ARG0 ( z2 person :quant ( z3 lot ) ) :ARG1 ( z4 planet :name ( z5 name :op "Mars" ) ) :ARG2 ( z6 nickname :poss z4 ) )