5 * 10^8 km =>2.5383 * 10^8 kmc = 3 * 10^5 km/s2.5383 * 10^8 / (3 * 10^5) =>25.383 * 10^7 / (3 * 10^5) =>8.461 * 10^2 =>846.1 secondsThe average amount of time it takes for light to travel between the Earth and Mars is 846.......
1.692182050191407911527009783071
So, the average distance between the Earth and Mars is roughly 1.6922 AU
1.6922 * 150 * 10^6 km =>
1.6922 * 1.5 * 10^8 km =>
2.5383 * 10^8 km
c = 3 * 10^5 km/s
2.5383 * 10^8 / (3 * 10^5) =>
25.383 * 10^7 / (3 * 10^5) =>
8.461 * 10^2 =>
846.1 seconds
The average amount of time it takes for light to travel between the Earth and Mars is 846.1 seconds.
Each planent rotates around the sun independent of each other so the distances between Earth and Mars are constantly changing.
The minimum distance is 54,510,620 km
The maximum distance from Earth to Mars is 401,355,980 km
Dividing by the speed of light in free space at 2.997 x 10^5 km/s gives...
Min time = 3.03 min
Max time = 22.29 mins
Technically speaking, at the furthest distance the radio signal or "space ship" would have to travel through the sun. It is not practical to think that a signal would be strong enough or a spaceship resilient enough to do this. So, you would need to wait until the two planets had a line of sight not effected by the sun, its radio-magnetic interference or its gravitational pull.
