Nasa's Kepler space telescope has discovered several new planets, including an 'older, bigger cousin to Earth', that that shares many characteristics with our world.
The new planet, called Kepler-452b, is more than 1,000 light years away and orbits a star similar to our Sun. It is also 60 per cent larger than Earth but lies in an orbital region where temperatures are thought to be mild enough to be suitable for life.
Dr Jon Kenkins, from Nasa's Ames Research Centre in Moffett Field, California, said: "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 six 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."
Kepler-452b is located in a star system 1,400 light years from Earth and evidence collected from the Kepler telescope indicates that it has a rocky surface. The new planet also has a 385-day orbit around its star, which is only five per cent longer than a year on Earth.
John Grunsfeld, associate administrator of Nasa's Science Mission Directorate in Washington DC, said: "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 Two."
The new findings will be submitted for publication in the Astrophysical Journal.