That rainbow you’re looking at is actually a magic bridge between worlds.
It’s called Bifrost, and it connects Asgard (the god realm) to Midgard (Earth). It’s protected by Heimdallr, a god with a fancy horn, a cool horse, and a real goddam love of gold. It’s his job to keep an eye out for the start of Ragnarok, essentially the end of the world via flood, but he gets to drink mead while he waits. Sounds like a pretty sweet gig to us.