Well-known planet hunter Geoff Marcy and scientists from the University of California, Berkeley ([U.C. Berkeley] and the University of Hawaii, Manoa announced exciting news yesterday. By computing data from the Kepler Space Mission, they figured out the number of Earth-like planets in the Milky Way orbiting stars like the Sun. The number? Tens of billions!
A press release from U.C. Berkeley quoted graduate student Erik Petigura, who was in charge of the team that analyzed the data. “When you look up at the thousands of stars in the night sky, the nearest sun-like star with an Earth-size planet in its habitable zone is probably only 12 light years away and can be seen with the naked eye. That is amazing,” Petigura said.
But the potential number of Earth-like planets orbiting in the Goldilocks Zone of stars where temperatures are “just right” for life, doesn’t mean that all the planets will be habitable. As Marcy warned, “Some may have thick atmospheres, making it so hot at the surface that DNA-like molecules would not survive. Others may have rocky surfaces that could harbor liquid water suitable for living organisms,” Marcy said. “We don’t know what range of planet types and their environments are suitable for life.”
What does it all mean? Now that we know that potentially habitable planets are so common, hopefully scientists will be able to detect if the atmospheres around planets orbiting stars closest to our Sun contain the ingredients for life. Scientists may be closing in on the mystery of alien life!