One of the things I really like about Star Wars is when we begin to draw the parallels between fiction and reality, using science to explain things.

So how about this article from the earther.com team showing the science behind the planet Crait:

One of the most visually striking elements of The Last Jedi—aside from the epic space battles, of course—is Crait, the glittering mineral world that becomes the focal point of the film’s final act. But as alien as this planet seems, Crait was shot right here on Earth, meaning there’s loads of real-world geology, ecology, and climate science behind this Resistance hideout.

It has a little spoiler, if you have already seen the movie, worth the read: follow the link.