有史以來第一張土星衛(wèi)星地圖

有史以來第一張土星衛(wèi)星地圖，使它成為外星生命的有力候選

Scientists on Monday unveiled the first global geological map of Saturn’s moon Titan, including vast plains and dunes of frozen organic material and lakes of liquid methane, illuminating an exotic world considered a strong candidate in the search for life beyond Earth.

科學(xué)家們于本周一公布了土星的衛(wèi)星“泰坦”(Titan)的第一幅全球地質(zhì)圖，其中包括廣闊的平原、布滿冰凍有機(jī)物質(zhì)的沙丘和液態(tài)甲烷的湖泊。這幅地圖向人們展示了一個被認(rèn)為是在地球之外尋找生命強(qiáng)有力候選者的奇異世界。

The map was based on radar, infrared and other data collected by NASA’s Cassini spacecraft, which studied Saturn and its moons from 2004 to 2017. Titan, with a diameter of 3,200 miles (5,150 km), is the solar system’s second-biggest moon behind Jupiter’s Ganymede. It is larger than the planet Mercury.

這張地圖是根據(jù)美國宇航局卡西尼號飛船收集的雷達(dá)、紅外和其他數(shù)據(jù)繪制的，該飛船在2004年至2017年對土星及其衛(wèi)星進(jìn)行了研究。泰坦直徑3200英里(5150公里)，是太陽系僅次于木星木衛(wèi)三的第二大衛(wèi)星。它比水星還大。

Organic materials — carbon-based compounds critical for fostering living organisms — play a leading role on Titan.

有機(jī)物質(zhì)——碳基化合物對培養(yǎng)生物至關(guān)重要——在泰坦上起著主導(dǎo)作用。

“Organics are very important for the possibility of life on Titan, which many of us think likely would have evolved in the liquid water ocean under Titan’s icy crust,” said planetary geologist Rosaly Lopes of NASA’s Jet Propulsion Laboratory in California.

美國宇航局噴氣推進(jìn)實(shí)驗(yàn)室的行星地質(zhì)學(xué)家羅莎莉·洛佩斯說：“有機(jī)物對泰坦上生命的可能性非常重要，我們之中有許多人認(rèn)為，泰坦冰冷外殼下的液態(tài)海洋可能發(fā)展出生命。”。
 

Reuters

“Organic materials can, we think, penetrate down to the liquid water ocean and this can provide nutrients necessary for life if it evolved there,” added Lopes, who led the research published in the journal Nature Astronomy.

“我們認(rèn)為，有機(jī)物質(zhì)可以滲透到液態(tài)水海洋中，如果在那里進(jìn)化的話，將可以為生命提供必要的營養(yǎng)。”洛佩斯補(bǔ)充說，他領(lǐng)導(dǎo)了發(fā)表在《自然天文學(xué)》雜志上的這項(xiàng)研究。

On Earth, water rains down from clouds and fills rivers, lakes and oceans. On Titan, clouds spew hydrocarbons like methane and ethane — which are gases on Earth — in liquid form due to the moon’s frigid climate.

在地球上，水從云層中落下，充滿了河流、湖泊和海洋。在泰坦上，由于月球寒冷的氣候，云層會噴出甲烷和乙烷等碳?xì)浠衔?mdash;—它們是地球上的氣體——以液態(tài)形式存在。

Rainfall occurs everywhere on Titan, but the equatorial regions are drier than the poles, said study co-author Anezina Solomonidou, a European Space Agency research fellow.

歐洲航天局研究員、研究合著者阿尼齊娜·索洛莫尼杜(Anezina Solomonidou)說，泰坦上到處都有降雨，但赤道地區(qū)比兩極干燥。

Plains (covering 65 percent of the surface) and dunes (covering 17 percent of the surface) made up of frozen bits of methane and other hydrocarbons dominate Titan’s mid-latitudes and equatorial regions, respectively.

由冰凍的甲烷和其他碳?xì)浠衔锝M成的平原(覆蓋65%的地表)和沙丘(覆蓋17%的地表)分別控制著泰坦的中緯度和赤道地區(qū)。

Titan is the only solar system object other than Earth boasting stable liquids on the surface, with lakes and seas of full of methane being major features at its polar regions. Hilly and mountainous areas, thought to represent exposed portions of Titan’s crust of water ice, represent 14 percent of the surface.

泰坦是除了地球以外唯一一個表面有穩(wěn)定液體的太陽系天體，其極地地區(qū)的主要特征是充滿甲烷的湖泊和海洋。泰坦水冰外殼裸露部分的丘陵和山區(qū)占地表的14%。

“What is really fun to think about is if there are any ways that those more complex organics can go down and mix with water in the deep icy crust or deep subsurface ocean,” JPL scientist and study co-author Michael Malaska said.

噴氣推進(jìn)實(shí)驗(yàn)室的科學(xué)家、該研究的合著者邁克爾·瑪拉斯卡說:“真正有趣的是，這些更復(fù)雜的有機(jī)物是否能以某種方式進(jìn)入到深海的冰殼或深海的地下，并與水混合。”

The map was created seven years before the US space agency is set to launch its Dragonfly mission to dispatch a multi-rotor drone to study Titan’s chemistry and suitability for life. Dragonfly is scheduled to reach Titan in 2034.

這張地圖是在美國航天局(US space agency)準(zhǔn)備發(fā)射蜻蜓任務(wù)(Dragonfly mission)的七年前繪制的，目的是派遣一架多旋翼無人機(jī)來研究泰坦的化學(xué)性質(zhì)和對生命的適應(yīng)性。蜻蜓計(jì)劃將于2034年到達(dá)泰坦。