Using the Kepler satellite, astronomers have found thousands of stars strewn throughout the Milky Way, many of which are surrounded by a number of exoplanets (planets not in our own Solar System) at various distances from their host star. This data, however, does not tell us anything about the habitability of all those untold planets. However, a group of researchers at the Niels Bohr Institute at the University of Copenhagen have devised a method to calculate the probability of solar systems within the Milky Way that contain habitable exoplanets.
Part of the trick lies in a weakness with NASA’s Kepler satellite, designed to locate either stars or massive planets orbiting close to their host stars. That leaves out the possibility of a number of smaller stars located within the sweet spot for habitability.