Out of roughly 100 billion stars in the Milky Way galaxy, a new analysis of Kepler data shows that around 17 percent of them have Earth-sized planets orbiting them, meaning there could be as many as 17 billion Earth-sized worlds. Kepler’s mission is to find and document Earth-sized planets at greater distances. The more planets discovered with Earth-like orbits in the habitable zone, the greater the chances of extraterrestrial life.
Being a similar size to Earth isn’t the only qualification for a life-sustaining planet, there are other criteria…
#5. Does it contain the essentials elements for building and sustaining life (carbon, hydrogen, oxygen, nitrogen and phosphorus – arguably iron as well.)?
#4. Is it nice and warm during parts of the year and a little chillier during other parts of the year?
#3. Are there little people all making noises, yelling, waving and holding big signs saying “this speck contains life”? (ala Horton Hears a Who) #2. Is it pristine and beautiful and does it contain enough inner wealth so we might lay it to waste in an orgy of self indulgence?