About 500 light-years away in the constellation Cygnus lives a star, which, though smaller and redder than the sun, has a planet that may look awfully familiar.

With a diameter just 10 percent bigger 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.

Scientists on the hunt for Earth's twin are focused on worlds that could support liquid surface water, which may be necessary to brew the chemistry of life.