The asteroids and minefields say "Play on any fleet. Until the beginning of your next turn, Blasts and Squadrons cannot be played on ships in that fleet."
I can't tell if "zones" and "fleets" are interchangeable, so I'm not sure if I can play one of these cards where I don't have a ship.
For example, if I lose my last ship in the green zone, can I play an Asteroids card as a sort of shield to protect my command ship until my next turn, or can I only play the card when there are ships in that area?
My kids and I are pretty sure "fleet" means one or more ships and "zone" means where you put them.