By ‘habitable’ I mean planets that are neither too cold nor too hot but occupy a sweet spot that would be conducive to life as we know it existing. By combining actual data, from the Kepler space observatory launched by NASA in 2009 to look for Earth-like planets orbiting other stars, with statistical analysis, scientists have come up with an estimate of 15-30 billion habitable planets in our Milky Way galaxy alone. That seems like a lot, even if that number is tiny compared to the estimated 1011 stars in the galaxy. [Read more…]
