It has been said many times: we inhabit a planet that is a blue miracle in the middle of darkness. Will miracles similar to Earth exist elsewhere in the universe?
The Kepler space telescope has found more than 2,000 exoplanet candidates, and we have already found, in total, more than 4,000 since we began searching around 1995. Currently, we have found 55 potentially habitable exoplanet.
Only in our galaxy, the Milky Way, there are about three hundred billion stars, around which about fifty billion planets orbit. Of those, five hundred million would be within what astronomers call the 'habitable strip', neither too cold nor too hot to hold water in a liquid state, which is most likely associated with the existence of life as we know it.
Drake's equation
The American astronomer Frank Drake formulated an equation in 1961 to calculate the existence of advanced civilizations in the nearby universe. The rate of planet formation is measured with seven parameters that indicate which planets are within the habitable band: how many of them could contain civilizations, how many of them would have survived this technological development; And then we have the factor L, which is time.
According to this equation, there could be 100,000 inhabited worlds in our galaxy.
