"Life Form Found" on Saturn's Titan(2012真題)(土衛(wèi)六上發(fā)現(xiàn)了生命跡象)
Scientists say they have discovered hints of alien life1 on the Saturn's moon2. The discovery of a sort of life was announced after researchers at the US space agency，NASA3，analyzed data from spacecraft Cassini4,which pointed to，the existence of methane-based form of life on Saturn's biggest moon.
科學(xué)家們說，在土衛(wèi)六上發(fā)現(xiàn)了外星生命跡象并宣布了這一發(fā)現(xiàn)。美國國家航空航天局(NASA)的研究者們對卡西尼號探測器所傳回來的數(shù)據(jù)進(jìn)行了分析，數(shù)據(jù)表明，土星衛(wèi)星中的一顆衛(wèi)星有以甲烷為基礎(chǔ)的生命的存在跡象。
Scientists have reportedly discovered clues showing primitive alien beings are "breathing" in Titan's dense atmosphere filled with hydrogen.
據(jù)報道，科學(xué)家們已經(jīng)找到了在土衛(wèi)六高濃度氫氣大氣層里“呼吸”的原始外星生命的線索。
They argue that hydrogen gets absorbed before hitting Titan's planet-like surface covered with methane lakes and rivers. This，they say，points to the existence of some"bugs"5 consuming the hydrogen at the surface of the moon less than half the size of the Earth.
他們認(rèn)為，氫氣在到達(dá)布滿甲烷河流湖泊的土衛(wèi)六類似行星一樣的表層前就已經(jīng)被吸收了。這就證明在這個不及半個地球大小的衛(wèi)星表面有某種微生物在依靠氫氣生存。
"We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan，similar to the way we consume oxygen on Earth，"says NASA scientist Chris McKay."If these signs do turn out to be a sign of life，it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."
美國國家航空航天局的科學(xué)家Chris Mckay說，“我們提出有氫氣的消耗，是由于它是土衛(wèi)六上生命賴以生存的顯而易見的氣體，就像我們地球上用氧氣呼吸一樣。如果這些跡象最終證明是生命的跡象，它會加倍令人興奮，因?yàn)樗鼤硗耆煌诘厍蛏纤牡诙N生命?！?BR> To date，scientists have not yet detected this form of life anywhere，though there are liquid-water-based microorganisms on Earth that grow well on methane or produce it as a waste product. On Titan, where temperatures are around 90 Kelvin6(minus 290 degrees Farenheit) ，a methane based organism would have to use a substance that is liquid as its medium for living processes, but not water itself. Water is frozen solid on Titan's surface and much too cold to support life as we know it.
時至今日，盡管地球上的依賴液體水的微生物在甲烷里生長良好或把它作為廢物排出，科學(xué)家在任何地方都沒有探測到這種生命的形式。在土衛(wèi)六上，絕對溫度達(dá)到90度(相當(dāng)于攝氏-273.15度)，依賴于甲烷的微生物不得不用某種液體物質(zhì)作為生存的介質(zhì)，這種液體不是水，水在土衛(wèi)六上會凍成冰塊，不能融化。我們知道，冰塊太冷不能維持生命。
Scientists had expected the Sun's interactions with chemicals in the atmosphere to produce a coating of acetylene on Titan's surface. But Cassini detected no acetylene on the surface.
科學(xué)家們原指望太陽與大氣層中的化學(xué)物質(zhì)相互作用會在土衛(wèi)六上產(chǎn)生一層乙炔。但卡西尼號在它的表面沒有探測到乙炔。
The absence of detectable acetylene on the Titan's surface can very well have a non-biological explanation，said Mark Allen，a principal investigator7 of the NASA Titan team.
Mark Allen是美國宇航局土衛(wèi)六項(xiàng)目組的主要負(fù)責(zé)人，他說道，既然在土衛(wèi)六的表面沒有探測到乙炔，那就充分說明上面沒有生物。
"Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed，"Allen said. "We have a lot of work to do to rule out8 possible non-biological explanations. It is more likely that a chemical process，without biology，can explain these results."
Allen說：“科學(xué)界的保守主義者們建議，要做出土衛(wèi)六上有生物的結(jié)論，首先必須對土衛(wèi)六上所有沒有生物的觀點(diǎn)做出回應(yīng);要排除土衛(wèi)六上可能沒有生物的觀點(diǎn)，我們?nèi)沃氐肋h(yuǎn)。極為可能的是，一種化學(xué)過程而非生物學(xué)能解釋這些結(jié)果?！?BR> 詞匯：
Saturn /'sætən/ n.土星 methane/'mi:θein/ n.甲烷，沼氣
Titan/'taitən/ n.土衛(wèi)六 acetylene/ə'setili:n/ n.乙炔
alien/'eiljən/ n.外星人;adj.外星球的;相異的
conservatism/kən'sʒ:vətizəm/ n.保守主義,守舊
注釋：
1.hints of alien life：外星生命跡象。
2.the Saturn's moon：指土衛(wèi)六(Titan) 。土衛(wèi)六又稱泰坦星，是土星衛(wèi)星中的一顆。
3.NASA：美國國家航空航天局的縮寫，全稱是： National Aeronautics and Space Administration。
4.spacecraft Cassini：卡西尼號探測器，以出生于意大利的法國天文學(xué)家卡西尼的名字命名，其任務(wù)是環(huán)繞土星飛行，對土星及其大氣、光環(huán)、衛(wèi)星和磁場進(jìn)行深人考察。1997 年10 月15日，重六噸的“卡西尼”號星際探測器被發(fā)射飛往土星的軌道。這是上世紀(jì)發(fā)射的最后一艘行星際探測的大飛船?！翱ㄎ髂帷碧栍昧藢⒔吣陼r間，在2004 年7月1日飛達(dá)土星軌道。
5.bugs：微生物。非正式口語表達(dá)，所以使用了引號。
6.Kelvin：可翻譯成“絕對溫度”。Kelvin Scale ，絕對溫標(biāo)，開氏溫標(biāo)，是由Kelvin 勛爵于19世紀(jì)中葉發(fā)明的溫度計量方法，其零度相當(dāng)于攝氏一273. 15" C ，被認(rèn)為是宇宙中最低溫度。這種溫度計量方法多為科學(xué)家使用。
7.principal investigator：研究項(xiàng)目負(fù)責(zé)人
8.rule out：排除……的可能性
練習(xí)：
1 .What have scientists found about Saturn?
A They have found a new moon orbiting Saturn.
B They have found methane-based life on Saturn.
C They have found methane-based life on Titan.
D They have found earthlike life on a Saturn's moon.
2. What do scientists say about Titan?
A There are life clues there.
B There is acetylene there.
C Water on Titan exists in the form of ice.
D Rivers and lakes there contain life formls.
3. To date,scientists have not yet detected this form of life.(paragraph 5)What does"this form of life" refer to?
A Water-based life.
B Methane-based life.
C Liquid-water-based microorganisms.
D Gas-based life.
4. What can be inferred from what Allen said?
A Scientists have different arguments over whether there is life on Titan.
B Scientists all agree that there is life on Titan.
C Scientists all suggest that a biological explanation is reasonable.
D Scientists all agree that a non-biological chemical reaction is a possible explanation.
5. Which of the following can replace the title of this passage?
A Earthlike Living Beings Found on Titan.
B Finding of One More Moon of Saturn.
C Titan,a New Satellite Found.
D A different Life Form, a Possibility.
答案與題解：
1. C 短文的第一段提供了答案。該段告訴讀者，科學(xué)家在土星的衛(wèi)星土衛(wèi)六( Titan )上發(fā)現(xiàn)了生命的跡象，這些生命的存在是以甲烷為基礎(chǔ)的。
2.A根據(jù)第二段“Scientists have reportedly discovered clues showing primitive alien beings are 'breathing' in Titan's dense atmosphere filled with hydrogen.”，說明土衛(wèi)六(Titan)有生命跡象。因此A是答案。
3. B this form of life 指的是土衛(wèi)六( Titan )上以甲烷為生命基礎(chǔ)呼吸氫氣的生物，即該文討論的主題。
4.A科學(xué)家至今對土衛(wèi)六是否存在生物有不同的觀點(diǎn)和解釋。Allen 說要做出土衛(wèi)六上有生物的結(jié)論，首先必須對Titan 上沒有生物的觀點(diǎn)做出回應(yīng);要排除土衛(wèi)六上可能沒有生物的觀點(diǎn)，我們還須付出努力。所以只有A是正確選擇。
5.D該短文的主題是，科學(xué)家在土衛(wèi)六( Titan )上發(fā)現(xiàn)了一種與地球生物不同的生命形式的跡象，即以甲烷為生命基礎(chǔ)呼吸氫氣的生物，但科學(xué)家還未能最后驗(yàn)證這一發(fā)現(xiàn)。第四段中的一個句子能夠揭示該短文的主題：“If these signs do turn out to be a sign of life, it would bedoubly exciting because it would represent a second form of life independent from water-based life on Earth.”
Scientists say they have discovered hints of alien life1 on the Saturn's moon2. The discovery of a sort of life was announced after researchers at the US space agency，NASA3，analyzed data from spacecraft Cassini4,which pointed to，the existence of methane-based form of life on Saturn's biggest moon.
科學(xué)家們說，在土衛(wèi)六上發(fā)現(xiàn)了外星生命跡象并宣布了這一發(fā)現(xiàn)。美國國家航空航天局(NASA)的研究者們對卡西尼號探測器所傳回來的數(shù)據(jù)進(jìn)行了分析，數(shù)據(jù)表明，土星衛(wèi)星中的一顆衛(wèi)星有以甲烷為基礎(chǔ)的生命的存在跡象。
Scientists have reportedly discovered clues showing primitive alien beings are "breathing" in Titan's dense atmosphere filled with hydrogen.
據(jù)報道，科學(xué)家們已經(jīng)找到了在土衛(wèi)六高濃度氫氣大氣層里“呼吸”的原始外星生命的線索。
They argue that hydrogen gets absorbed before hitting Titan's planet-like surface covered with methane lakes and rivers. This，they say，points to the existence of some"bugs"5 consuming the hydrogen at the surface of the moon less than half the size of the Earth.
他們認(rèn)為，氫氣在到達(dá)布滿甲烷河流湖泊的土衛(wèi)六類似行星一樣的表層前就已經(jīng)被吸收了。這就證明在這個不及半個地球大小的衛(wèi)星表面有某種微生物在依靠氫氣生存。
"We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan，similar to the way we consume oxygen on Earth，"says NASA scientist Chris McKay."If these signs do turn out to be a sign of life，it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."
美國國家航空航天局的科學(xué)家Chris Mckay說，“我們提出有氫氣的消耗，是由于它是土衛(wèi)六上生命賴以生存的顯而易見的氣體，就像我們地球上用氧氣呼吸一樣。如果這些跡象最終證明是生命的跡象，它會加倍令人興奮，因?yàn)樗鼤硗耆煌诘厍蛏纤牡诙N生命?！?BR> To date，scientists have not yet detected this form of life anywhere，though there are liquid-water-based microorganisms on Earth that grow well on methane or produce it as a waste product. On Titan, where temperatures are around 90 Kelvin6(minus 290 degrees Farenheit) ，a methane based organism would have to use a substance that is liquid as its medium for living processes, but not water itself. Water is frozen solid on Titan's surface and much too cold to support life as we know it.
時至今日，盡管地球上的依賴液體水的微生物在甲烷里生長良好或把它作為廢物排出，科學(xué)家在任何地方都沒有探測到這種生命的形式。在土衛(wèi)六上，絕對溫度達(dá)到90度(相當(dāng)于攝氏-273.15度)，依賴于甲烷的微生物不得不用某種液體物質(zhì)作為生存的介質(zhì)，這種液體不是水，水在土衛(wèi)六上會凍成冰塊，不能融化。我們知道，冰塊太冷不能維持生命。
Scientists had expected the Sun's interactions with chemicals in the atmosphere to produce a coating of acetylene on Titan's surface. But Cassini detected no acetylene on the surface.
科學(xué)家們原指望太陽與大氣層中的化學(xué)物質(zhì)相互作用會在土衛(wèi)六上產(chǎn)生一層乙炔。但卡西尼號在它的表面沒有探測到乙炔。
The absence of detectable acetylene on the Titan's surface can very well have a non-biological explanation，said Mark Allen，a principal investigator7 of the NASA Titan team.
Mark Allen是美國宇航局土衛(wèi)六項(xiàng)目組的主要負(fù)責(zé)人，他說道，既然在土衛(wèi)六的表面沒有探測到乙炔，那就充分說明上面沒有生物。
"Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed，"Allen said. "We have a lot of work to do to rule out8 possible non-biological explanations. It is more likely that a chemical process，without biology，can explain these results."
Allen說：“科學(xué)界的保守主義者們建議，要做出土衛(wèi)六上有生物的結(jié)論，首先必須對土衛(wèi)六上所有沒有生物的觀點(diǎn)做出回應(yīng);要排除土衛(wèi)六上可能沒有生物的觀點(diǎn)，我們?nèi)沃氐肋h(yuǎn)。極為可能的是，一種化學(xué)過程而非生物學(xué)能解釋這些結(jié)果?！?BR> 詞匯：
Saturn /'sætən/ n.土星 methane/'mi:θein/ n.甲烷，沼氣
Titan/'taitən/ n.土衛(wèi)六 acetylene/ə'setili:n/ n.乙炔
alien/'eiljən/ n.外星人;adj.外星球的;相異的
conservatism/kən'sʒ:vətizəm/ n.保守主義,守舊
注釋：
1.hints of alien life：外星生命跡象。
2.the Saturn's moon：指土衛(wèi)六(Titan) 。土衛(wèi)六又稱泰坦星，是土星衛(wèi)星中的一顆。
3.NASA：美國國家航空航天局的縮寫，全稱是： National Aeronautics and Space Administration。
4.spacecraft Cassini：卡西尼號探測器，以出生于意大利的法國天文學(xué)家卡西尼的名字命名，其任務(wù)是環(huán)繞土星飛行，對土星及其大氣、光環(huán)、衛(wèi)星和磁場進(jìn)行深人考察。1997 年10 月15日，重六噸的“卡西尼”號星際探測器被發(fā)射飛往土星的軌道。這是上世紀(jì)發(fā)射的最后一艘行星際探測的大飛船?！翱ㄎ髂帷碧栍昧藢⒔吣陼r間，在2004 年7月1日飛達(dá)土星軌道。
5.bugs：微生物。非正式口語表達(dá)，所以使用了引號。
6.Kelvin：可翻譯成“絕對溫度”。Kelvin Scale ，絕對溫標(biāo)，開氏溫標(biāo)，是由Kelvin 勛爵于19世紀(jì)中葉發(fā)明的溫度計量方法，其零度相當(dāng)于攝氏一273. 15" C ，被認(rèn)為是宇宙中最低溫度。這種溫度計量方法多為科學(xué)家使用。
7.principal investigator：研究項(xiàng)目負(fù)責(zé)人
8.rule out：排除……的可能性
練習(xí)：
1 .What have scientists found about Saturn?
A They have found a new moon orbiting Saturn.
B They have found methane-based life on Saturn.
C They have found methane-based life on Titan.
D They have found earthlike life on a Saturn's moon.
2. What do scientists say about Titan?
A There are life clues there.
B There is acetylene there.
C Water on Titan exists in the form of ice.
D Rivers and lakes there contain life formls.
3. To date,scientists have not yet detected this form of life.(paragraph 5)What does"this form of life" refer to?
A Water-based life.
B Methane-based life.
C Liquid-water-based microorganisms.
D Gas-based life.
4. What can be inferred from what Allen said?
A Scientists have different arguments over whether there is life on Titan.
B Scientists all agree that there is life on Titan.
C Scientists all suggest that a biological explanation is reasonable.
D Scientists all agree that a non-biological chemical reaction is a possible explanation.
5. Which of the following can replace the title of this passage?
A Earthlike Living Beings Found on Titan.
B Finding of One More Moon of Saturn.
C Titan,a New Satellite Found.
D A different Life Form, a Possibility.
答案與題解：
1. C 短文的第一段提供了答案。該段告訴讀者，科學(xué)家在土星的衛(wèi)星土衛(wèi)六( Titan )上發(fā)現(xiàn)了生命的跡象，這些生命的存在是以甲烷為基礎(chǔ)的。
2.A根據(jù)第二段“Scientists have reportedly discovered clues showing primitive alien beings are 'breathing' in Titan's dense atmosphere filled with hydrogen.”，說明土衛(wèi)六(Titan)有生命跡象。因此A是答案。
3. B this form of life 指的是土衛(wèi)六( Titan )上以甲烷為生命基礎(chǔ)呼吸氫氣的生物，即該文討論的主題。
4.A科學(xué)家至今對土衛(wèi)六是否存在生物有不同的觀點(diǎn)和解釋。Allen 說要做出土衛(wèi)六上有生物的結(jié)論，首先必須對Titan 上沒有生物的觀點(diǎn)做出回應(yīng);要排除土衛(wèi)六上可能沒有生物的觀點(diǎn)，我們還須付出努力。所以只有A是正確選擇。
5.D該短文的主題是，科學(xué)家在土衛(wèi)六( Titan )上發(fā)現(xiàn)了一種與地球生物不同的生命形式的跡象，即以甲烷為生命基礎(chǔ)呼吸氫氣的生物，但科學(xué)家還未能最后驗(yàn)證這一發(fā)現(xiàn)。第四段中的一個句子能夠揭示該短文的主題：“If these signs do turn out to be a sign of life, it would bedoubly exciting because it would represent a second form of life independent from water-based life on Earth.”