Question

The Curiosity rover on Mars is not operated by using a joystick from the Earth because the communication delay time is too long, that is, the time it takes for a light signal to make a round-trip between the Earth and Mars. Earth is 8 light minutes from the Sun. Mars orbits at about 12 light minutes from the Sun. What is the lowest possible communication delay time between the Earth and Mars?

(a) 4 minutes
(b) 8 minutes
(c) 12 minutes
(d) 24 minutes
(e) 40 minutes

Answer 1

The lowest possible communication delay time between Earth and Mars is 4 minutes, which occurs when both planets are closest on the same side of the sun.

Step-by-step explanation:

Understanding Communication Delays Between Earth and Mars

The lowest possible communication delay time between Earth and Mars occurs when the two planets are at their closest in their respective orbits. Given that Earth is 8 light minutes from the Sun and Mars is about 12 light minutes from the Sun, the two could theoretically be aligned on the same side of the sun at their nearest points. This would mean Mars is only 4 light minutes away from Earth's orbit around the sun.

The shortest distance light would have to travel between Earth and Mars would be the difference between their respective distances from the Sun, assuming a straight line. Hence, if we subtract Earth's 8 light minutes from Mars' 12 light minutes, we get 4 light minutes. This is the minimum possible time it would take for light to travel one way between the two planets, and consequently, the lowest possible communication delay time.

Therefore, the answer to the question, "What is the lowest possible communication delay time between the Earth and Mars?" is (a) 4 minutes.