By analyzing data from the Kepler Space Telescope and the M.W. Keck Observatory, they have determined that 22% of yellow stars(like our own sun) have a rocky, Earth-sized planet in the habitable zone. There are at least 40 billion yellow stars in the Milky Way, so that equates to 8.8 billion rocky planets in the habitable zone.
But that is only for yellow stars. Red dwarf stars are the most common type of star, and they account for about 75% of the stars in our galaxy. A study released earlier in 2013 found that about 6% of red dwarfs host a rocky planet in the habitable zone.
According to Geoff Marcy, co-author of the new study, when you combine these numbers, you get an estimate of 40 billion Earth-sized, rocky planets in the habitable zone. 40 billion! Of course, not all of these planets are going to be exactly like Earth. But with 40 billion possibilities, it is a safe bet that the number of planets like Earth, with water and life, is well into the billions.
And remember, that's only the Milky Way. There are at least 200 billion other galaxies in the Universe. 40 billion x 200 billion = 8,000,000,000,000,000,000,000.
So what these studies make clear is that Earth-like planets are very common.
Life is everywhere. Intelligent civilizations are everywhere.
The Universe is a home for life. That is the whole point. It is a place for life and consciousness to grow.
This knowledge will have a profound, mind-expanding effect on our humble Earth society. It no doubt will stimulate our curiosity about what is out there, and open our minds to the possibility of meeting people from another planet in the not-too-distant future.