“Using the properties of previously discovered exoplanets, we developed a simple metric of habitability for each planet that uses its mass and temperature to rate it on a scale of 0 to 1, where 1 is Earth-like, and 0 is so very not Earth-like. Plotting these values over time and taking the upper envelope yields a nice march towards habitability. Using a simple bootstrap sampling analysis, we calculated when a logistic curve fit to such an upper envelope would get to a habitability of approximately 1. And the likeliest time is early to mid-2011, or more precisely, early May 2011.”