A recent study run by astronomers of NASA has brought up the estimate that there are roughly 8.8 billion Earth-sized planets orbiting suns common to ours that have the chance of harboring life in the Milky Way galaxy alone. These planets are shown to be in the Goldilocks Zone, an area where it is neither too hot nor too cold, thus being a possible habitable zone. To put that into context, there are more of these possible life-sustaining planets than there are people currently living on Earth.
The study was conducted by having the Kepler telescope look at 42,000 stars and see how many Earth-like planets there were, then extrapolated that amount to the rest of the galaxy’s hundreds of billions of stars. The study only looked at suns that were roughly the same size as our own though, which is not the most common type of star.
If the Kepler study was concerned with Earth-like planets orbiting other sized suns in their Goldilocks Zone, the study’s co-author, Geoff Marcy estimated that there are roughly 40 billion right-sized and right-placed planets out in the Milky Way galaxy.
Marcy questioned why, if there were so many possible Earth-like planets, there is a deafening silence in our galaxy from advanced civilizations?