About 500 light-years away in the constellation Cygnus lives a star, which, though smaller and redder than the sun, has a planet that could look familiar.
With a diameter 10 percent larger than Earth’s, the newly found world is the first of its size found basking in the benign temperature region around a parent star where water, if it exists, could pool in liquid form.
Statistically speaking, Earth-sized planets orbiting in stars’ “habitable zones,” not too far away for water to freeze but not too close for it to vaporize, should be common, recent studies show.
Observations are difficult to come by. NASA’s Kepler space telescope spent four years staring at about 150,000 target stars looking for slight and repeated dips in their light caused by orbiting planets passing by, or transiting, relative to the telescope’s line of sight