Alright, let's just do the math. Here's a graph of the distance from Earth to Mars over the next few years. The current ping time is right around 11 minutes and 43 seconds for a signal to get from Earth to Mars (one way). That's over 23 minutes round trip for a ping.
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The current distance as of right now to Mars is 210,786,242 kilometers. That is 11 minutes and 43.1072 seconds to get a signal to the rover. Throw in a few more seconds for routing, etc.