NASA has revealed on Thursday that its Kepler space mission has found the first planet that is nearly the size of the Earth in the habitable zone.
The Kepler space telescope has been hunting for new exoplanets over the past several years and identifies potential planets by observing periodic dips in the stars' brightness.
The newly found planet, dubbed Kepler-452b, is around a sun-like star and to date is the smallest known planet orbiting in the habitable zone of a G2-type star. The so-called habitable zone refers to the area around a star where liquid water could pool on an orbiting planet's surface.
The super-Earth-size planet is 60 percent larger in diameter than Earth and while its composition and mass are yet to be determined, earlier research suggests that planets of this size are likely rocky.
The Kepler-452b also has a 385 day-orbit, 5 percent longer compared with that of the Earth's. It is likewise 5 percent farther from its parent star compared with the distance between the Earth and the sun. Its parent star, Kepler-452 is 6 billion years old or 1.5 billion years older than the solar system's sun and is 20 percent brighter albeit is has the same temperature as the sun.
Jon Jenkins, from NASA's Ames Research Center who led the team that discovered the new planet, said that the Kepler-452B can be thought of as an older and bigger cousin of the Earth giving scientists an opportunity to understand and reflect on the evolving environment of our planet.
Jenkins added that it is awe-inspiring to think that the planet has been in the habitable zone of its star for 6 billion years, which is longer compared with the Earth, and this length of time provides substantial opportunity for life to emerge if all the crucial conditions and ingredients for life exist on the planet.
"On the 20th anniversary year of the discovery that proved other suns host planets, the Kepler exoplanet explorer has discovered a planet and star which most closely resemble the Earth and our Sun," said NASA's Science Mission Directorate associate administrator John Grunsfeld,. "This exciting result brings us one step closer to finding an Earth 2.0."
The Kepler-452 system was found in the constellation Cygnus and is located 1,400 light-years away. The findings were presented in the seventh Kepler Candidate Catalog. The discovery will also be submitted for publication in the Astrophysical Journal.
