Abstract :
Earlier this year, astronomers announced the discovery of a planet not much bigger than Earth. Dubbed Kepler- 452b, the planet orbits a star like our own sun. Even more exciting, it orbits its star at just about the same distance that Earth orbits the sun, with a year that lasts just 20 days longer than our own. For the first time, astronomers had found a world that could be called-if not an Earth twin-at least a close cousin.
