Kepler mission discovers an Earth-like planet

NASA’s Kepler Space Telescope has confirmed the first near-Earth-sized planet orbiting another star like our Sun.

NASA scientists suggest the newly discovered planet – named Kepler-452b – is 60% larger in diameter than Earth and is 5% farther from its parent star than Earth is from the Sun. It is the first planet discovered orbiting in the area around a G-2 type star – the same class as our Sun – where liquid water could pool on the surface of 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. This exciting result brings us one step closer to finding an Earth 2.0.,” said John Grunsfeld, associate administrator of NASA’s Science Mission.

To determine the properties of the Kepler-452 system – where the newly discovered planet was found – the team conducted ground-based observations at the University of Texas at Austin's McDonald Observatory. They found Kepler-452 system is 1,400 light-years away from Earth. The parent star in the system is 6 billion years old – 1.5 billion years older than our Sun – and 20% brighter with 10% larger diameter than our Sun.

While Kepler-452b is larger than Earth, its 385-day orbit is only 5% longer. Its mass and composition have not yet been determined; however it is thought that Kepler-452b may be 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. 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,” said Jon Jenkins, Kepler data analysis leader at NASA's Ames Research Center in California.