What is the wavelength of a 22.75 x 10^9Hz radar signal? How long would it take a message sent as radio waves from Earth to reach Mars when Mars is (a) nearest Earth, (b) farthest from Earth? Assume that Mars and Earth are in the same plane and that their orbits around the Sun are circles (Mars is 230 x 10^6 km away from the Sun and earth is 149.6 x 10^ km away from the sun).