5.5  Lots of habitable planets!

Applying the methods you learned about in Sections 2 and 3, astronomers have reached startling conclusions about the number of potentially habitable planets there may be in our Galaxy. This draws on everything we know about the exoplanets discovered so far, and uses the correction for the probability factors. The conclusion is that there is likely to be a rocky planet in the habitable zone of one star in five!