Headline Image caption & credit: The Earth is certainly not alone in the cosmos. NASA Ames / W Stenzel A new NASA study has revealed just how many potentially habitable worlds there are in our galaxy. As things stand, the Earth is the only known example of a habitable world in the entire universe - even the other planets in our solar system, as far as we know, do not (or no longer) harbor life. On a galactic scale however, worlds capable of supporting life may be literally everywhere. According to new NASA research based on data from the now-defunct Kepler space telescope, roughly half of all stars with a similar temperature to our own are likely to host a terrestrial planet capable of supporting liquid water on its surface. This equates to around 300 million potentially habitable worlds across the Milky Way. Some of these could also be relatively close - as little as 20 light years away. "Kepler already told us there were billions of planets, but now we know a good chunk of those