Jack of Harts

One of the basic tenants of stellar geography is that friction causes heat.  In the same way that one rubs their hands together by pulling one’s muscles to warm them when cold, the tectonic plates of a planet or moon rubbing together due to the pull of gravity can cause them to warm in deep space.  This heat can melt rock into magma, or ice into water, even if only underground.  And it’s a fact of biological science, that where there is water, there is life.