Amazing news has come our way through the lens of the Kepler space telescope.
NASA announced on Thursday (July 23) that it had discovered the closest thing yet to a second Earth, orbiting a star 1,400 light years away (see artist's rendition above).
The planet, named Kepler-452b, is said to be about 60 percent larger than Earth and falls into the "habitable zone," the combination of conditions that could lead to life. Not only is the planet said to be similar to Earth, but its star -- located in the constellation of Cygnus -- is also very much like our sun. Kepler-452b orbits its star at approximately the same distance as the Earth circles our sun, although it takes a little longer, 385 days, to make its journey.
Additional data studied by NASA indicates that Kepler-452b could be a rocky planet, and that it's older than Earth. Its sun is older than ours too -- by 1.5 billion years -- and is growing hotter, just like ours will do a billion years from now.
John Grunsfeld, an associate administrator of NASA, 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 2.0."
There have been several candidates for "another Earth" in recent times, with the last one discovered about a year ago. However, that planet, Kepler-186f, was orbiting a dimmer dwarf star that would make the chances of life as we know it developing there less likely. On the other hand, the possibility of liquid water forming on the newly discovered planet's surface is greater -- which could lead to life.
Kepler has identified more than 1,000 exoplanets and thousands of potential ones since launching in 2009. although less than a dozen are firmly in the habitable zone. The telescope detects exoplanets by measuring small fluctuations in starlight as a planet crosses a star's path in Kepler's line of sight.
The best thing about all this? The SETI Institute is now focusing its search for signals on the Keplar-452 star system -- although so far it hasn't heard anything.