[Q&A] Fuel for Comet Tails, Detecting a Voyager's Crash, Driving Into Lava Tubes

Why don't comets run out of "tail fuel"? If Voyager crashes into something, can we tell it apart from a regular failure? What are the chances we will drive into a lava tube? Will satellite communication become dominant at some point? Answering all these and more in this Q&A show.