Suppose some astronauts have landed on Mars.
(a) When Mars and Earth are on the same side of the Sun and as close as they can be to one another, how long does it take for radio transmissions to travel one way between the two planets?
(b) Suppose the astronauts ask a question of mission control personnel on Earth. What is the shortest possible time they have to wait for a response? The average distance from Mars to the Sun is 2.28 × 1011m.