NASA announces discovery of potentially habitable planet in old space telescope data

NASA announced this week that it had discovered in older data evidence for an Earth-sized planet orbiting the habitable zone of a relatively nearby star, an encouraging sign for astronomers seeking evidence of planets elsewhere in the universe that may harbor and support life. 

The agency said in a press release on Wednesday that it had made the discovery when reviewing older data from the Kepler space telescope. Launched in 2009 and retired two years ago, that instrument was specifically designed to detect extrasolar planets, or "exoplanets," around stars in the Milky Way. 

Astronomers are continually searching for planets orbiting around the "habitable zones" of stars, an area in which a planet is close enough to receive a star's heat but far enough away that it can sustain the processes and materials---most importantly liquid water---necessary for life as we know it. The Kepler telescope detected several thousand such planets during its nine-year mission. 

NASA officials said a review of Kepler's archived data led them to discover a previously unnoticed planet which they titled Kepler-1649c. The planet "is only 1.06 times larger than our own planet. Also, the amount of starlight it receives from its host star is 75% of the amount of light Earth receives from our Sun – meaning the exoplanet's temperature may be similar to our planet’s, as well," the agency said in its press release. 

Kepler-1649c orbits its star much closer than our planet does to the Sun. Yet the exoplanet's star, which lies about 300 light years from Earth, is a red dwarf, with less volume and a lower energy output than the sun, meaning its habitable zone is much smaller. 

University of Texas at Austin researcher Andrew Vanderburg said information gathered by scientists over the years indicate that there are possibly a great many planets throughout the galaxy that humans could theoretically populate.

"The more data we get, the more signs we see pointing to the notion that potentially habitable and Earth-size exoplanets are common around these kinds of stars," he said.