Due to the position of the planets the Curiosity rover was pretty much left on it’s own for a month, space.com reports. This happens once every couple years and generally lasts for a few weeks to a month.
The main worry is that if they try to send a command to the rovers while this Mars Conjunction is going on it may not get all the data, and think it needs to blow itself up or become self aware or something. OK so maybe nothing that bad would happen, but it could cause the rovers to fall off a cliff or something.
Check out the article here, which has a pretty cool short video that explains what’s going on.