While Trump is an idiot, I'd like to point out that that's a mistranslation of the words he said: you need to understand that he doesn't speak English very well, so sometimes what he types and what is intended are two different things, a bit of translation is required. He didn't actually mean to suggest that the moon was part of Mars. No, what he actually meant to suggest was far more stupid. See, confusing the moon with one of Mars' satellites is simple ignorance: it's not inconceivable that anyone could've made the same mistake, even a well learned person on a particularly sleepy morning might make a pre-covfefe mistake. What Trump was trying to say, or what he claims he meant, was that we shouldn't be trying to get back to the moon, we should be going to Mars. The part about the moon being part of Mars is that the moon is a stepping point in order to get to Mars: set up a permanent base on the moon and it's easier to launch long journeys from there. So to recap: we should not be going to the moon as a stepping stone to get to Mars. Instead we should be going to the moon as a stepping stone to get to Mars.