Latency would be determined almost completely by the speed of light itself. Earth to Mars ranges from 5.5*10^10 to 4.0*10^11 m, and light travels 3*10^8 m/s.

Latency would be determined almost completely by the speed of light itself. Earth to Mars ranges from 5.5*10^10 to 4.0*10^11 m, and light travels 3*10^8 m/s. Earth-Mars latency is therefore from 3 to 22 minutes one-way.