We might even send them there to see themselves, but they might think they're dreaming. We could have them land there, let them step on it, and they will think they are in canada. We can point at the Earth, but they would think it's the moon. Then our only option is to break their helmets, but they would just tell us "Nice try, but the invisible demon from that fairytale is just chocking me! Then we just leave them there, because obviously we can't convince them.