For the first time ever an Earth-sized planet has been discovered orbiting the habitable zone of a sun within our own Milky Way galaxy. Astronomers are also claiming that there exists a high probability it could also be harbouring life.
NASA’s Kepler telescope spotted the exoplanet orbiting an M-class red dwarf star some 500 light years from Earth, and it has since been named Kepler-186f after the instrument used to find it. Due to the planet’s distance from its star it has been speculated it could potentially have similar properties to our own Earth, meaning liquid water crucial for the development of life may be present. As
Elisa Quintana, research scientist at the SETI Institute at NASA’s Ames Research Center, explains:
“Finding a habitable-zone planet comparable to Earth in size is a major step forward. M dwarfs are the most numerous stars. The first signs of other life in the galaxy may well come from planets orbiting an M dwarf.”
Of the almost 2,000 planets discovered over the past 20 years, just 20 orbit within the so-called “habitable zone” and NASA scientist Thomas Barclay said the discovery of Kepler-186f was a milestone in attempts to discover other Sun–Earth type analogous systems. As Barclay, explains:
“Kepler-186f orbits a star that is cooler and dimmer than the sun so while we may have found a planet that is the same size as Earth and receives a similar amount of energy to what Earth receives, it orbits a very different star, so perhaps instead of an Earth twin we have discovered an Earth cousin.”