VOA慢速英語：木衛(wèi)二可能存在生命

Jupiter’s Moon Europa May Be Top Candidate for Life

木衛(wèi)二可能存在生命

A fresh look at old data is giving scientists a new reason to consider Europa, a moon orbiting the planet Jupiter, as a leading candidate in the search for life beyond Earth.

對老數(shù)據(jù)的一次重新審視讓科學(xué)家們又有理由將木衛(wèi)二作為尋找地外生命的重要選擇。

The reason: evidence of water from the moon shooting into space.

原因就是找到了來自該衛(wèi)星的水汽噴向太空的證據(jù)。

NASA, the American space agency, noted an unusual shape -- a bend -- in Europa's magnetic field in 1997. That was the year when NASA's Galileo spacecraft passed close to the moon. For a time, it was about 200 kilometers above the surface.

美國宇航局提到了1997年木衛(wèi)二的磁場出現(xiàn)了一次不同尋常的彎曲。這一年，美國宇航局的伽利略號航天器從該衛(wèi)星近處掠過。該航天器一度距離其表面只有大約200公里。

Scientists reported earlier this month on their reexamination of the Galileo data. They now think this bend in the magnetic field could be explained by an active geyser in an underground ocean. The scientists believe the spacecraft traveled through a plume of water.

科學(xué)家們本月早些時候報告了他們對伽利略數(shù)據(jù)的重新審視。他們目前認(rèn)為，磁場的這種彎曲可以用地下海洋中的一處活間歇泉來解釋?？茖W(xué)家們認(rèn)為航天器經(jīng)過了一處羽狀水汽。

Elizabeth Turtle is a planetary scientist with the Johns Hopkins University Applied Physics Laboratory. She told reporters that Europa does have a lot of the qualities that are necessary for life was we know it.

伊麗莎白·泰托(Elizabeth Turtle)是約翰霍普金斯大學(xué)應(yīng)用物理實驗室的行星科學(xué)家。她對記者表示，木衛(wèi)二確實具有很多我們已知生命需要的特質(zhì)。

"There's water. There's energy. There's some amount of carbon material. But the habitability of Europa is one of the big questions that we want to understand," said Turtle.

泰托表示：“那兒有水，有能量，有一定數(shù)量的碳物質(zhì)。但是木衛(wèi)二的可居住性是我們最想了解的重要問題之一。“

"And one of the really exciting things about detection of a plume is that that means there may be ways that the material from the ocean — which is likely the most habitable part of Europa because it's warmer and it's protected ... to come out above the ice shell," she added.

她補充說：”關(guān)于探測到羽流最令人興奮的是，這意味著可能會有海洋物質(zhì)從冰殼下噴發(fā)出來。而海洋可能是木衛(wèi)二最宜居的地方，因為它更溫暖并且受到了保護。“

University of Michigan space physicist Xianzhe Jia led the latest study, which was published in the journal Nature Astronomy.

密歇根大學(xué)空間物理學(xué)家賈獻哲(Xianzhe Jia，音譯)領(lǐng)導(dǎo)了這項最新的研究，并發(fā)表在《自然天文學(xué)》雜志上。

The findings support other evidence of plumes from Europa, whose ocean may contain two times as much water as all of Earth's oceans. In 2012, NASA's Hubble Space Telescope collected evidence of ultraviolet radiation which suggests a plume.

這些研究結(jié)果支持了來自木衛(wèi)二羽流的其它證據(jù)。木衛(wèi)二海洋水量可能是地球所有海洋水量的兩倍。2012年，美國宇航局的哈勃太空望遠(yuǎn)鏡搜集到的紫外線輻射證據(jù)表明存在羽流。

NASA will get a close-up look from a new spacecraft as part of the space agency's Europa Clipper mission. That spacecraft could be launched as soon as June 2022. The agency says this could provide a chance to examine plumes for signs of life from Europa's ocean, some of which may be microscopic.

作為”木衛(wèi)二飛艇任務(wù)”一部分，美國宇航局將用新的航天器做一次近距離探測。該航天器可能于2022年6月發(fā)射。美國宇航局表示，這可能會給探測羽流尋找木衛(wèi)二海洋生命跡象提供證據(jù)。

Experts consider Europa to be among the top candidates for life in our solar system. But it is not the only one.

專家認(rèn)為木衛(wèi)二是太陽系中存在生命的首選之一。但是它不是唯一的。

For example, NASA's Cassini spacecraft examined plumes from Enceladus, a moon of the planet Saturn. The water from Enceladus's ocean contained hydrogen from hydrothermal vents, an environment that may have given rise to life on Earth.

例如，美國宇航局的卡西尼號航天器探測了土衛(wèi)二的羽流。來自土衛(wèi)二海洋的水汽含有深海熱泉的氫氣。木衛(wèi)二的這種環(huán)境可能會產(chǎn)生地球上的生命。

Europa is a little smaller than Earth's moon. Its ocean is buried under about 15 to 25 kilometers of ice. Experts believe the ocean itself to be anywhere from 60 to 150 kilometers deep.

木衛(wèi)二比月亮略小。它的海洋被埋在大約15到25公里深的冰下。專家認(rèn)為，海洋本身的深度在60到150公里之間。

I'm Pete Musto.

皮特·瑪索報道。