In a study published in the journal Proceedings of the National Academy of Sciences it has been announced that the primary mission of the Kepler Space Telescope has been completed. Kepler’s goal was to determine how many of the 100 billion stars in our galaxy possess potentially habitable planets and it has been statistically concluded that 20%, or 20 billion stars possess Earth-like planets in their habitable zone.
Kepler achieved its mission through analysis of 150,000 stars over a period of four years in which it reported 3,000 candidate planets. It is important to note that Earth-like does not mean habitable; determining a planet’s habitability is a bit of a wild guess at this stage as the requirements for life might be wider than we suspect, or not, we just don’t know. Determining habitability will come later when we develop much more powerful spectrographs and telescopes in order to determine things like atmosphere composition.
What does this mean for us? Not exactly a whole lot but here is something cool: when you look up at the stars at night, you can know that the nearest Earth-like planet is suspected to be less than 12 light years from Earth and to orbit a star that can be seen with the unaided eye. If that’s not cool, I don’t know what is. (x)