Scientists have discovered a new planet that is similar to Earth. The planet, called Kepler-186f, is slightly (no more than 10%) larger than ours and probably has seasons like Earth does. But while this news is exciting, there is a lot that we still don't know about Kepler-186f.
NASA – the research organization that found the new planet – is always looking for planets with similar conditions to Earth's. However, space scientist Thomas Barclay says that we should think of Kepler-186f as an "Earth cousin" and not as an "Earth twin." Like our planet, it is made of rock. It is also likely to have water on its surface, which is unusual, but in many other ways Kepler-186f is different from
Whereas Earth takes 365 days to go around the sun, Kepler-186f only takes 130 days to go around its star. Earth is brighter, too; at midday on Kepler-186f, the sky would look the same as during our sunset. And scientists don't yet know about the emperature on the new planet. There is a good chance that Kepler-186f is much hotter than Earth.
Unfortunately, humans will not be traveling to Kepler-186f any time soon. It is 500 light-years away, so the journey would take a lot more than 500 years. NASA is still looking for other livable planets which are closer and easier to understand.
地球公轉太陽一圈需要365天；克卜勒-186f公轉其恆星一圈僅需130天。地球也較為明亮，克卜勒-186f 的午時，天空看起來已如地球的夕陽景象。況且，科學家尚未得知此新行星的氣溫，克卜勒-186f 的氣候很有可能比地球炎熱許多。