by Erika Nesvold | Jan 18, 2014 | Daily Paper Summaries
Title: Superhabitable Worlds Authors: René Heller and John Armstrong First Author’s Institution: McMaster University Status: Published in Astrobiology Note: This journal article covers two topics that we thought each deserved its own astrobite. Yesterday’s astrobite discussed the first half of the paper, about the effects of tidal heating on habitability. Today’s astrobite explores the concept of superhabitability.Introduction to SuperhabitabilityLet’s talk about the Copernican principle. This idea states that we (humans, Earth, the Solar System, etc) are not special. We’re not the center of the universe, and there’s no particular reason to believe that we’re unique in the Universe. We’re just average, middle-of-the-road, ordinary. In a lot of cases this has turned out to be true — Earth is not the center of the Solar System, the Solar System is not the center of the Galaxy, and the Milky Way Galaxy is only one of many. So this concept is really useful when trying to understand cosmology, but what does it mean in the context of our search for habitable worlds? The Copernican principle would imply that the reason life exists on Earth is not because Earth is a unique, magical place. Instead, life exists on Earth because Earth happens to have the right physical conditions to allow life to evolve, and those physical conditions probably exist elsewhere, too. So our search for “habitable” worlds is often conflated with a search for “Earth-like” worlds — planets and moons with the same size, density, and surface temperature as Earth.But what if we’re not average? What if Earth isn’t your standard suburb of habitability, but actually a rough neighborhood, habitable-but-only-barely? In an...
