I think they are on the night side of the moon, which is still well lit by that full earth. They do need to be in some sort of air bubble to be able to talk to each other, as sound doesn’t carry in a vacuum.
That’s because those kids get more sun, and thus have healthy levels of vitamin D at the time that their immune systems are figuring out which antigens are truly dangerous.
I think they are on the night side of the moon, which is still well lit by that full earth. They do need to be in some sort of air bubble to be able to talk to each other, as sound doesn’t carry in a vacuum.