This artist's concept compares Earth (left) to the new planet, called Kepler-452b, which is about 60 percent larger in diameter. Credits: NASA/JPL-Caltech/T. Pyle 
This size and scale of the Kepler-452 system compared alongside the Kepler-186 system and the solar system. Kepler-186 is a miniature solar system that would fit entirely inside the orbit of Mercury. Credits: NASA/JPL-CalTech/R. Hurt 
There are 4,696 planet candidates now known with the release of the seventh Kepler planet candidate catalog - an increase of 521 since the release of the previous catalog in January 2015. Credits: NASA/W. Stenzel 
Since Kepler launched in 2009, twelve planets less than twice the size of Earth have been discovered in the habitable zones of their stars. Credits: NASA/N. Batalha and W. Stenzel 
This artist's concept depicts one possible appearance of the planet Kepler-452b, the first near-Earth-size world to be found in the habitable zone of star that is similar to our sun. Credits: NASA/JPL-Caltech/T. Pyle
WASHINGTON (July 23, 2015)— NASA announced some big news in the hunt for Earth-like planets.
Earth has a long-lost cousin!
NASA announced the discovery in a press release Thursday:
The Kepler mission has confirmed the first near-Earth-size planet in the “habitable zone” around a sun-like star. This discovery and the introduction of 11 other new small habitable zone candidate planets mark another milestone in the journey to finding another “Earth.”
“This exciting result brings us one step closer to finding an Earth 2.0,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate at the agency’s headquarters in Washington.
According to NASA, Kepler-452b is 60 percent larger in diameter than Earth and is considered a super-Earth-size planet. While its mass and composition are not yet determined, previous research suggests that planets the size of Kepler-452b have a good chance of being rocky.
“We can think of Kepler-452b as an older, bigger cousin to Earth, providing an opportunity to understand and reflect upon Earth’s evolving environment,” said Jon Jenkins, Kepler data analysis lead at NASA’s Ames Research Center. Jenkinsled the team that discovered Kepler-452b. “It’s awe-inspiring to consider that this planet has spent 6 billion years in the habitable zone of its star; longer than Earth. That’s substantial opportunity for life to arise, should all the necessary ingredients and conditions for life exist on this planet.”
The Kepler-452 system is located 1,400 light-years away in the constellation Cygnus. The research paper reporting this finding has been accepted for publication in The Astronomical Journal.
