太阳系外发现一颗可能有生命的超级地球

Point a high-powered telescope at the constellation Cetus, the sea monster, and it is just possible to make out a dim red dwarf star shining in the tail. 

使用高倍率望远镜观察鲸鱼座（Ceuts，名为海怪），也只能勉强看到星座尾部有一颗昏暗的红矮星在发光。

Although it might seem unspectacular, orbiting around that star is a rocky planet that could hold the answer to whether we are alone in the universe. 

Scientists say the planet is a 'Super-Earth' which is the best place to look for signs of life outside of the Solar System. 

Early indications suggest it has an atmosphere, and sits within the 'Goldilocks Zone' where it is neither too hot nor too cold for liquid water to exist. 

And it is only 40 light years from Earth meaning that it could be possible to send a signal. 

"This is the most exciting exoplanet I've seen in the past decade," said lead author Jason Dittmann of the Harvard-Smithsonian Center for Astrophysics. 

"We could hardly hope for a better target to perform one of the biggest quests in science -- searching for evidence of life beyond Earth."

The planet was found by an international team of scientists who have been studying data from European Space Observatory’s High Accuracy Radial velocity Planet Searcher (HARPS) instrument which looks for regular changes in brightness of stars, which suggests a planet is passing by in orbit. 

The new world - dubbed LHS 1140b - is ten times closer to its parent star than Earth but because a red dwarf is far cooler than our own yellow dwarf, the planet still sits in the habitable zone. 

"The present conditions of the red dwarf are particularly favourable -- LHS 1140b spins more slowly and emits less high-energy radiation than other similar low-mass stars," added team member Nicola Astudillo-Defru from Geneva Observatory, Switzerland.