People can do more than one thing at once. We spend a lot of money studying the Earth, from space and the surface. Studying other planets helps understand thing

People can do more than one thing at once. We spend a lot of money studying the Earth, from space and the surface. Studying other planets helps understand things about the Earth that would be difficult to figure out by only studying the Earth. Studying other stars helps us understand the Sun. In another comment you say: > If we are able to reliably extract energy from lava/volcanoes, That's already being done at scale, especially in Iceland.