A single realization of the habitability of extrasolar planets over time.

2013-02-20T23:01:45Z (GMT) by Samuel Arbesman Gregory Laughlin

values for the extrasolar planets are plotted, with those of the upper envelope (maximum for a given year of discovery) indicated in black. The black curve is the logistic best-fit curve of the upper envelope, using a nonlinear model, where and . The horizontal grey line indicates the maximum value of , the presence of an Earth-like habitable planet.