For most of us, meteors are by far the ultimate planet killers. All it takes is one direct hit to suddenly wipe all life from the face of a world. But, rather than taking life away from a planet, what if a meteor impact is the reason that the world is habitable in the first place?
In the story I'm writing, humanity discovers a habitable exo-world known as Elysium. It's an Earth-sized rocky moon orbiting elliptically around a Saturn like gas giant (known as Aphrodite) that is just over 4 times the mass of Jupiter.
Elysium is well outside of the habitable zone of it's binary parent stars. But the moon's surface is kept nice and warm thanks to a giant impact crater that dominates it's face (known as the Cinder Fields).
Although the crater should have cooled and sealed up thousands of years ago, the tidal force of Aphrodite on the moon's surface has kept it open and hot, warming up the planet's atmosphere and surface through the Cinder Fields.
Could a world like this actually work in real life?