By Tim Binnall
An exhaustive new study from NASA has concluded that there could be a whopping 300 million habitable worlds in the Milky Way galaxy. The intriguing determination reportedly came by way of a two-year-long project in which 44 astronomers studied data collected by the Kepler Telescope. Seen as the culmination of that exoplanet-hunting spacecraft's work, one of the scientists on the team marveled to the New York Times that "this is the science result we've all been waiting for" and "the reason that Kepler was selected for flight in December 2001."
Specifically, the team combed through the voluminous Kepler data and found that "half the stars similar in temperature to our Sun could have a rocky planet capable of supporting liquid water on its surface." Taking into account insights gleaned from the European Space Agency's Gaia mission, which looked at the type of energy emitted from these stars and how it is absorbed by the planets that orbit them, they ultimately came to the figure of 300 million potentially habitable exoplanets in our galaxy based on "the most conservative estimate that 7% of Sun-like stars host such worlds." Considering that is a cautious guess, scientists say, the true number of such exoplanets could be significantly higher.
While that enormous number should give optimism to those hoping to eventually find some kind of intelligent life out there in space, some researchers cautioned that one might wish to temper their expectations. That's because scientists have yet to identify an exoplanet which is the same size as Earth and possesses a matching orbit around a Sun-like star, which are, as of yet, the only conditions known to produce life. Be that as it may, it stands to reason that there ought to be at least one such world among the 300 million theoretically habitable exoplanets in our galaxy. How long it may take us to find it, of course, remains to be seen.