NASA's Kepler space telescope has made a new round of discoveries: two planetary systems, both of which are home to a total of three planets within the habitable zone. As such, it is possible that each planet could have a surface temperature capable of liquid water and supporting life. The findings were recently published in the journal Science.
The two planetary systems are called Kepler-62 and Kepler-69, with the first being home to five planets and the second being home to two. Of those, planets 62e, 62f, and 69c are the planets of interest. While all are bigger than Earth, the (probably) rocky planet Kepler-62f is said to be only 40-percent bigger, thus earning the designation of the closest habitable-zone exoplanet near Earth's size.
The next smallest is Kepler-69e, which NASA says is 60-percent bigger than Earth, and last is Kepler-69c, which is 70-percent larger. The latter planet is the only of the three that orbits a star close in size to our sun. Like other discoveries, no one knows yet whether any of these three planets could harbor life, but such finds inspire those ideas, and take us one step closer to discovering an Earth twin.
NASA's Science Mission Directorate associate administrator John Grunsfeld said: "The Kepler spacecraft has certainly turned out to be a rock star of science. The discovery of these rocky planets in the habitable zone brings us a bit closer to finding a place like home. It is only a matter of time before we know if the galaxy is home to a multitude of planets like Earth, or if we are a rarity."