A new exoplanet candidate has just burst onto the scene, and it may be one of the best alien worlds yet on which to search for extraterrestrial life . It's just 18 light-years away: a super-Earth named GJ 251c with a minimum mass about 3.84 times that of our own planet. The most exciting part? It's smack-bang in its star's habitable zone – an orbital distance neither too far from nor too close to the star to support life. "The exoplanet is in the habitable or the 'Goldilocks Zone,' the right