Especially if you breathe air, it's very hard to get from planet A to planet B, because there's no air in between. But if you breathe air you're dead as soon as you're off the planet, unless you have a spaceship.
Especialmente si respiras aire, Es muy difícil ir de un planeta A a un planeta B, porque no hay aire entre ellos, pero si respiras aire estás muerto en cuanto salgas del planeta, a no ser que