地球不孤單 NASA宣佈發現新地球

NASA on Thursday announced the discovery of Kepler-452b, the most Earth-like planet ever found. Located 1,400 light-years from our planet, NASA called it "Earth 2.0," because it's the first planet discovered in the habitable zone of a G star similar to our sun。

週四，美國國家航空航天局(以下簡稱爲NASA)宣佈發現開普勒-452b，是迄今爲止與地球最爲相近的行星。該行星距離地球1400光年，NASA將其命名爲“地球2.0”，因爲它是第一顆人類在宜居帶裏與太陽相似的恆星附近發現的行星。

"We can think of Kepler-452b as an older, bigger cousin to Earth, providing an opportunity to understand and reflect upon Earth's evolving environment," said Jon Jenkins, the Kepler data analysis lead at NASA's Ames Research Center。“

我們可以不妨將開普勒-452b視爲地球年紀較大，體積也較大的“老表”。從它身上我們可以瞭解並反思地球所演變的環境，”NASA艾姆斯研究中心開普勒數據分析的領隊瓊·詹金斯如是說。

The planet is 5 percent farther away from its star than Earth is to the sun, making for a slightly longer year of 385 days, but gets similar light because its sun is 20 percent brighter than our own。

該行星與其恆星之間的距離要比地球與太陽的距離遠上百分之五，因此它一年(公轉週期比地球稍長)爲385天，但光線與地球相差無幾。因爲它的恆星亮度要比太陽高百分之二十。

"The sunshine from this star would feel very similar to the sunshine from our star," Jenkins told reporters。

詹金斯告訴記者：“開普勒-452b上的陽光跟我們地球上的陽光感覺是差不多的。”

NASA believes the planet has a mass about five times more massive than Earth's, with a rocky surface below a thicker atmosphere than our own. Gravity would be about twice as strong on Kepler-452b as it is on Earth, NASA said。

NASA認爲，該行星的質量大約要比地球的質量大5倍，其岩石表面上空的大氣層要比地球的大氣層厚許多。而開普勒-452b的引力是地球引力的2倍。

The planet is located in the Kepler-452 system in the constellation Cygnus. Its sun has the same surface temperature as our own, but has a diameter that is 10 percent larger。

該行星位於開普勒-452星系裏的天鵝座。它的恆星表面溫度與地球一樣，但直徑要比地球大上百分之十。

While NASA scientists have no idea if Kepler-452b's atmosphere is conducive to life, they do know that there has been plenty of time for organisms to develop。

雖然NASA的科學家們無法確定開普勒-452b的大氣環境是否有利於生命的形成，但他們知道在該星球上有足夠的時間來形成微生物有機體。

"It's awe-inspiring to consider this planet spent 6 billion years in the habitable zone of its star, which is longer the age of the Earth," Jenkins said. "That is considerable time and opportunity for life to arise somewhere on its surface or oceans if all the necessary conditions for life exist on this planet."

“這顆行星在其恆星的宜居帶裏存在了60億年，這可比地球的年齡大多了，想想都覺得令人敬畏，”詹金斯說道，“如果該行星上具備適宜生命存在的所有必備條件，這時間足以讓其表面形成生命了。”