 New discovery is likely to be a rocky world in the ‘Goldilocks’ zone of its parent star where the temperature is just right for liquid water to flow 
 
 An alien world that orbits a distant star in the constellation of Lyra may be the most Earth-like planet ever found outside the solar system. Scientists at the Harvard-Smithsonian Center for Astrophysics announced the discovery at a meeting of the American Astronomical Society in Seattle on Tuesday, along with seven other planets that also lie in the habitable zones of their stars. It is about a third larger than Earth, receives about two thirds as much starlight, and has a 60% chance of being rocky, according to a report to be published in The Astrophysical Journal. They also push Kepler's tally of vetted, confirmed worlds to just over 1,000, marking a milestone in the mission's epochal search for alien Earths. Before their discovery, the exoplanets most similar to our own were Kepler 186f, which is 10% larger than Earth and receives a third as much light, and Kepler 62f, which is 40% larger and gets about 41% as much light. The task was expected to take just over three years because many things can cause stars to dim besides transiting planets, and astronomers would need to glimpse the periodic recurrence of any mirror Earth's transit not once or twice but three times to be convinced that any particular dimming was due to a planet. David Kipping, a co-author on the study, said that Kepler 438b and 442b were “as close to Earth analogues as we’re going to find in the Kepler data”. At the same meeting, Fergal Mullally, a staff scientist and Kepler team member at NASA's Ames Research Center at Moffett Field, Calif., announced an additional 554 yet-to-be-confirmed candidate planets added to Kepler's catalogue, bringing its total candidate count to 4,175 possible worlds. Three of the new crop sit within the "habitable zone" of their host stars - and one in particular is rocky, like Earth, as well as only slightly warmer. According to lead author Guillermo Torres, another astronomer at the CfA, this validation process took more than a year and a half and relied on some of the world's largest telescopes as well as intensive simulation runs on a NASA supercomputer. Astronomers are keenly waiting on the next generation of telescopes, including Hubble’s replacement, the James Webb Space Telescope, and the European Extremely Large Telescope, which is being built in the Atacama desert in Chile, to help them examine the atmospheres of distant planets for signs of life.
– If you're sick of Earth and have a spacecraft capable of traveling hundreds of light-years, astronomers have spotted the most promising destination yet. Kepler-438b is a newly-confirmed potential "Earth twin" detected by the Kepler Space Telescope, the BBC reports, one of eight confirmed new exoplanets. The planet, about 470 light-years away in the Lyra constellation, is the most Earth-like ever spotted outside our solar system. It's only slightly larger than our planet, sits in the "Goldilocks zone" where the temperature is right for liquid water to flow, and probably has a rocky surface, researchers say. Its dwarf star gives it around 40% more heat than our planet receives from the sun, and its years are just 35 days long. The latest find brings the number of confirmed worlds spotted by Kepler—including Kepler-186f, the previous most Earth-like find—to just over 1,000, with more than 3,000 still to be vetted, reports Scientific American. To search for clues that life may exist on Kepler-438b and other planets, researchers plan to examine Kepler data for signs of moons, which help stabilize orbits and temperatures, and for gas giants in the same solar system, which reduce the odds of catastrophic asteroid hits, the Guardian reports. (Last month, Kepler data revealed a possible water world, or "mini-Neptune," 180 light-years away.)