> Earth is in a peculiar position such that the delta V of getting to orbit will also get you to anywhere else in the solar system fairly quickly. Tangent: On

> Earth is in a peculiar position such that the delta V of getting to orbit will also get you to anywhere else in the solar system fairly quickly. Tangent: One of my favorite answers to the Fermi paradox (not mutually exclusive with others) is that much of the life in the universe is stuck at the bottom of huge gravity wells ("super Earths") that make space flight immensely difficult and expensive, making the development of a space industry far less likely. It's a variant of the rare Earth hypothesis. Not only might Earth be rare for its stability and long-lived biosphere but also for the fact that it's large enough to hold onto a thick atmosphere and water but not so large that you can't get off it with relatively benign (compared to higher energy alternatives) chemical propellants. Increases in the mass of Earth would make space launch exponentially not linearly harder. Getting anything non-trivial off a super-Earth would probably require nuclear or hybrid (e.g. LANTR) rockets, which are problematic for ground launch in a biosphere. They'd also be a lot more costly.