科學家發(fā)現(xiàn)系外“鉆石”行星群

 

An exoplanet, called WASP-12b which is about 1,200 light years from Earth and 1.4 times the mass of Jupiter has been considered suitable for life existence, although a little hot. And its sibling planets could even be made of diamonds, according to new research findings.

一顆名為WASP-12b系外行星適合生存，盡管有點兒熱。此行星距離地球1200光年、質量為木星1.4倍的。而與其同屬一個星系的行星有可能由鉆石構成。

A team led by researcher Nikku Madhusudhan of Princeton University and scientist Joe Harrington of the University of Central Florida monitor WASP-12b during one of its orbits, particularly in the instants before it passed behind its home star. In those brief moments, the light from the star would flow through the planet's atmosphere, allowing astronomers to study the wavelengths produced and infer the atmosphere's chemical composition.

　　由美國普林斯頓大學的研究員尼庫•馬杜蘇丹和佛羅里達中部大學的科學家喬•哈林頓領導的一個研究小組監(jiān)測WASP-12b的一次繞軌運行情況，特別是從其母恒星后面經(jīng)過的那一刻。在那一剎那，恒星發(fā)出的光會穿透行星的大氣層，天文學家據(jù)此研究行星產生的波長，并推斷行星大氣層中所含的化學成分。

They found some exoplanets, WASP-12b included, have carbon-rich chemistry: Some have atmospheres with a carbon-to-oxygen ratio of about 0.5. As for WASP-12b, however, there was more than twice the concentration of carbon as usual and almost 100 times more methane than expected.

　　他們發(fā)現(xiàn)，一些系外行星具有碳濃度高的化學特性，包括WASP-12b在內，即它們大氣層中的碳氧比率約為0.5。不過，WASP-12b的碳濃度要比通常情況高出兩倍多，而且所含甲烷的濃度幾乎是預計的100倍。

That has big implications for extraterrestrial biology, since life is based on carbon, and methane - which is made up of carbon and hydrogen - is a byproduct of metabolism. The planet's carbon-heavy atmosphere could retain heat and light, providing energy for life to get started and thrive. That life would have to survive on comparatively little oxygen and water, and would have to be very tolerant of methane.

　　這對于地外生物學來說意義重大。因為生命建立在碳的基礎上，而由碳和氫構成的甲烷又是新陳代謝的副產品。行星大氣層中高濃度碳可以留住光和熱，為生命的出現(xiàn)和成長提供能量。這些生命必須氧氣和水相對較少的環(huán)境下生存，而且還要忍受甲烷。

　　As for some of the planets formed along with WASP-12b, they could easily be smaller, with rocky formations made not of silica, like Earth's, but of graphite or - given enough time and enough pressure - precious diamonds.

　　而和WASP-12b一起的另外一些行星很可能體積更小，巖層不是像地球那樣由硅石構成，而是由石墨或者珍貴的鉆石（如果有充足的時間和壓強）構成。