At its closest approach, Mars is 56 million km from Earth. How long would it take to send a radio message from a space probe of Mars to earth when the planets are at this closest distance?
Because, distance between earth and mars s= 56million km = 56*10^(6+3) m
Distance between earth and mars:
s = 56million km
= 56*10^(6+3) m
= 5.6*10^(10) meters
Speed of radio waves in free space c = 3*10^8 m/s