The only cases it happen ( I'll could check but I'm 90% sure ) is when the planet you've selected collide with a bigger planet, or got burned by it's star. Sometimes other planets come close to yours and change dramatically it's orbit, I've seen some been send on the star's surface.
Life cannot destroy planet, no matter how far they've evolved I didn't added this feature.
I've encountered few times and learned how to not choose planets with such risks, at least less risky. If you need advises ( and spoils... ) you can still PM me.
I know it's a bit confusing, even more as the game over screen don't give any information. I've got a load of work to make it easier to understand but I must say it's not an easy task as the game is (over?) complicated.