Finish the in-game tutorial.

Focus a planet that is not Earth.

Turn on Lock surface and look around that world.

Spawn an asteroid or a comet that orbits another body

Have a spawned asteroid or comet strike a world.

Spawn a star

Give a world a ring set from the Create menu

Create something... Theoretical?

Move the Earth and heat it up until the oceans are gone.

Move the Moon inside the Roche limit

In Binary star dance, let the two stars merge.

Tidally lock Earth for at least 10 game years.