Oh yes. In Admin, you can create page types. You can learn more on https://learn.getgrav.org/content/content-pages.
Basically, your theme has the option to define all the page types it needs. The Learn theme, used to build the docs, provides a docs and chapter page types: https://github.com/getgrav/grav-theme-learn2/tree/develop/templates
Antimatter, the default theme, is more generalist and provides different page types: https://github.com/getgrav/grav-theme-antimatter/tree/develop/templates
You can see here
default
blog (blog posts list)
item (single blog post)
and a few more.
So you can create a planet.html.twig and a movie.html.twig templates, and create your pages:
pages/01.venus/planet.md
pages/02.mars/planet.md
pages/03.shining/movie.md
Now, to make them easily editable in Admin, you need to put a blueprint in your theme. Like these ones. This is a bit more advanced, but we have a great documentation for that.