Astronomers have declared a major milestone in the search for life outside of Earth, saying they have found the first Earth-sized planet that could support human life.
The planet is located about 500 light years away and is one of five orbiting a red dwarf star that is is smaller and cooler than our sun.
Yet what makes it particularly compelling is that it resides in a temperate region where liquid water could exist, said Elisa Quintana of the Search for Extraterrestrial Intelligence (SETI) Institute.
It’s one of about 20 planets found by NASA’s Kepler space telescope to orbit their planets in a habitable zone.
Most of those planets, however, are too large, meaning they could have thick atmospheres of hydrogen and helium similar to those on Jupiter and Saturn.
Scientists have determined that the ideal size for a habitable planet is something smaller than 1.5 times the size of Earth. The newly discovered planet, called Kepler-186f, is estimated to have a radius about 1.1 times the Earth’s.
The team led by Quintana and Steve Howell, Kepler project scientist, confirmed their findings using high resolution images from two telescopes in Hawaii.
More precise information about Kepler-186f’s atmosphere must await the building and launch of NASA’s Webb telescope.
Since August 2013, the Kepler telescope has been hobbled by the failure of two of four gyroscopes that helped the craft maintain its position in space.
But it has continued sending the observations it is still able to make.
The research is published in the journal Science.