What if there were 6-billion Earth-like planets, all in our own solar system?
We all know about the infamous Carl Sagan quote about the pale blue dot we call planet Earth, in regards to the famous photo of the Earth taken by the Voyager 1 Spacecraft in 1990, a photo taken explicitly at Carl Sagan’s request.
“Look again at that dot,” he said of the photo, one of the most famous pictures of Earth ever taken. “That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you’ve ever heard of, every being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor, and explorer, every teacher of morals, every corrupt politician, every ‘superstar,’ every ‘supreme leader,’ every saint and sinner in the history of our species lived there — on a mote of dust suspended in a sunbeam.”
The quote is famous — it became a book title for Sagan and is one of his most often cited diatribes about the nature of the universe — but it also now may have a bigger meaning, now that astronauts have discovered through the use of the Kepler space telescope that there may be some 6-billion Earth-like planets in the Milky Way galaxy alone.
According to astronomers at the University of British Columbia, which collected data from 9-years of the Kepler telescope and amassed information on about 200,000 stars, it looks like there could be about 6 billion Earth-like planets. They found that there are likely about 5 planets per “Sun” in the solar system, otherwise known as G-type stars.
“Our milky way has as many as 400 billion stars, with seven percent of them being G-type. That means less than six billion stars may have Earth-like planets in our galaxy,” Jaymie Matthews, a co-author of the study and astronomer said.
Earth-like planets are described as rocky, about the same size as our own pale blue dot, and in the “habitable” zone of a Sun, conditions that would allow life of some form to flourish. Of course, there are probably many more Earth-like planets than just six billion — given that there are many solar systems — but it is still confounding to think about.