Call it “New Earth” or “Earth 2.0”: NASA’s Kepler mission has for the first time found a new planet that is approximately the same size as our homeworld and which lies in the “habitable zone” of a sun-like star, the US space agency revealed this afternoon.
The planet has been dubbed Kepler-452b and is said to be the smallest planet discovered thus far orbiting an G2-type star at a distance suitable for liquid water to pool on its surface. It is one of a dozen new small habitable zone worlds discovered during the Kelpler’s search for a “new Earth” and brings the number of confirmed new worlds discovered during the mission to 1,030.
“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 John Grunsfeld, associate administrator of NASA’s Science Mission Directorate. “This exciting result brings us one step closer to finding an Earth 2.0.”
Super-earth sized planet is believed to be rocky
According to NASA officials, Kepler 452-b is approximately 60 percent larger in diameter than the Earth, resulting in its classification as a super-Earth sized planet. Currently, the composition and mass of the planet have not been determined, but based on previous findings, the researchers believe the odds are good that the size of the new planet means it will be rocky.
Despite being significantly larger than Earth, its orbit is only five percent longer than the planet we call home (385 days). NASA reported that Kepler-452b is five percent further away from its parent star, the six-billion year old Kepler-452, than Earth is from the sun. Furthermore, officials from the agency note that Kepler-452 is approximately 1.5 billion years older, nearly identical in temperature, 10 percent larger and 20 percent brighter than the Milky Way’s sun.
Jon Jenkins, Kepler data analysis lead at the NASA Ames Research Center in Moffett Field, California and the head of the team that located Kepler-452b, said that the planet is essentially “an older, bigger cousin to Earth.” The discovery, he added, provides experts the chance “to understand and reflect upon” the “evolving environment” of the planet we call home.
“It’s awe-inspiring to consider that this planet has spent 6 billion years in the habitable zone of its star; longer than Earth,” he added. “That’s substantial opportunity for life to arise, should all the necessary ingredients and conditions for life exist on this planet.”
More than 500 other potential planets discovered as well.
The discovery of the planet and the entire Kepler-452 system was confirmed with the assistance of ground-based observations conducted by astronomers at the University of Texas at Austin’s McDonald Observatory, the Fred Lawrence Whipple Observatory on Mt. Hopkins, Arizona, and the WM Keck Observatory atop Mauna Kea in Hawaii, according to NASA.
Measurements conducted at those facilities not only helped give NASA a better idea of the new system’s properties, but also made it possible to verify that Kepler-452b was indeed a planet, to ensure that the size and brightness levels of its host star were correct and to increase the accuracy of the planet and its orbit. A paper detailing the discovery of the new planet, which is located 1,400 light-years from Earth, will be published in The Astronomical Journal.
The Kepler team has also added more than 500 new exoplanet candidates based on an analysis of observations conducted between May 2009 and May 2013. This brings the number of candidates, which are planets found by the Kepler mission that still need to be verified as actual planets, thus far to 4,696. Twelve of those new potential planets orbit in their star’s habitable zone and have a diameter no larger than twice that of Earth’s, including nine orbiting G2 stars like the sun.
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Feature Image: This artist’s concept compares Earth (left) to the new planet, called Kepler-452b, which is about 60 percent larger in diameter. (Credit: NASA/JPL-Caltech/T. Pyle)
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