Last week, the SETI Institute put out a study that claimed there could be as many as 300 million potentially habitable worlds in our galaxy. That’s a pretty good number, considering that nearly every star is likely to have (or have had) at least one planet (according to another study). What’s more, given the distribution of stars and planets in the Milky Way, some of those potentially habitable worlds could be fairly close to us. This isn’t just some “pie in the sky” guesstimate. Scientist Jeff Coughlin (of the SETI Institute) and a team of researchers used Kepler Space Telescope data as well as observation sets from the European Space Agency’s GAIA mission to come to their conclusions.
An artist’s conception of Kepler-186f. It’s the first confirmed Earth-size planet found orbiting a distant star in its habitable zone. Credit: NASA Ames/JPL-Caltech/T. Pyle
Estimating the Number of Such Worlds
So, if there ARE 300 million potentially habitable worlds “out there”, what might they be like? Anybody who reads science fiction probably has a good idea. Visiting other planets is a staple of that genre. For those of us who read SF, the existence of worlds with life on them is not ...