2016年托福聽力真題背景知識:宇宙中的宜居星球

字號:

2016年2月28日聽力考試第1篇Lecture綜述:   教授講了外太空有沒有生命存在的問題。如果有生命存在,就必須有液態(tài)水。舉例說人類發(fā)現(xiàn)了土衛(wèi)六和Gliese 581g,很像地球,但是特別遠(yuǎn),可能有生命存在。這顆星球比地球大,也有液態(tài)水。但是它只有一邊能曬到陽光,一邊不能。于是學(xué)生問另一邊是不是會frozen了呢,教授說不會,因?yàn)榭諝馐橇鲃拥?。后來又說天空的顏色是因?yàn)榭諝庵泻刑佳趸?,根?jù)濃度和光的反射會呈現(xiàn)不同的顏色,地球是藍(lán)色的,這個星球是紅色的。將這顆星球跟地球?qū)Ρ?,還真的可能有生命存在。最后教授說,其實(shí)我們離它并不遠(yuǎn),未來肯定會有更多更準(zhǔn)確的信息。   關(guān)于幾顆宜居星球榜首的星球,你需要知道的知識:   1. Gliese 581g (2011年) 相似度89% 最新托福聽力真題背景知識:宇宙中的宜居星球托福聽力真題背景知識:宇宙中的宜居星球"/>   Scientists have discovered a planet which could have the most Earth-like environment ever found - raising a 'very compelling case' for life there. Gliese 581g, located around 123trillion miles away, orbits a star at a distance that places it squarely in the habitable - or Goldilocks - zone, Nasa said. The research, the product of more than a decade of observations at the WM Keck Observatory in Hawaii, suggests the planet could contain liquid water on its surface.   科學(xué)家們發(fā)現(xiàn)了一顆迄今為止與地球環(huán)境最相像的行星,這為外星生命的存在提供了一個“非常令人信服的例子”。NASA稱,這顆名為Gliese 581g的行星離地球大約123萬億英里,它圍繞著一顆恒星運(yùn)轉(zhuǎn),與恒星的距離不遠(yuǎn)不近,恰好位于適宜居住的區(qū)域,或者宜居帶內(nèi)。科學(xué)家們根據(jù)夏威夷WM凱克(WM Keck)天文臺10多年的觀測進(jìn)行研究,發(fā)現(xiàn)這顆行星的表面可能含有液態(tài)水。   It found that Gliese 581g has a mass three to four time the Earth's and orbits its star in just under 37 days. Its mass indicates that it is probably a rocky planet with a definite surface and enough gravity to hold on to an atmosphere.   Gliese 581 has two previously detected planets that lie at the edges of the habitable zone where the atmosphere is just the right temperature for liquid water to exist - one on the hot side (planet c), the other on the cold face (planet d).   研究發(fā)現(xiàn),Gliese 581g的質(zhì)量是地球的3-4倍,公轉(zhuǎn)周期僅為37天不到。Gliese 581g的質(zhì)量顯示,它可能是一顆巖態(tài)行星,有著固定的表面和足以吸住大氣層的引力。 宜居帶內(nèi)的大氣溫度適宜,可能有液態(tài)水存在。之前發(fā)現(xiàn)的2顆Gliese 581行星都位于宜居帶的邊緣,其中一顆位于熱側(cè)(行星c),另一顆位于冷側(cè)(行星d)。 最新托福聽力真題背景知識:宇宙中的宜居星球   The planet is tidally locked to the star, meaning that one side is always facing the star and basking in perpetual daylight, while the side facing away from the star is in perpetual darkness.   One effect of this is to stabilize the planet's surface climates, according to Vogt. The most habitable zone on the planet's surface would be the line between shadow and light (known as the 'terminator').   這顆行星與恒星潮汐鎖定,這意味它的一面始終朝向恒星,永久沐浴在日光之中,而背離恒星的一面則永久處于黑暗之中。Vogt稱,這一現(xiàn)象的一個作用是使該行星的表面氣候穩(wěn)定。這顆行星上最適宜居住的區(qū)域是黑暗與光明之間的交界線(被稱為“明暗界線”)。   Read more:   http://www.dailymail.co.uk/sciencetech/article-2066185/Gliese-581g-Newly-discovered-planet-just-like-Earth-contain-liquid-water.html   http://article.yeeyan.org/view/260717/238621
    2. Titan (2011年) (土衛(wèi)六,土星的第六顆衛(wèi)星)   土星的大衛(wèi)星土衛(wèi)六擁有太陽系中神奇的表面環(huán)境,充滿液態(tài)甲烷和碳?xì)浠衔锏氖澜缈赡艽嬖谟腥さ纳C绹的螤柎髮W(xué)天體生物學(xué)家和化學(xué)家認(rèn)為土衛(wèi)六在許多方面是地球的孿生兄弟,土衛(wèi)六是太陽系的衛(wèi)星,比水星還大,表面的大氣壓力比地球要高一點(diǎn),而且也有大氣。更重要的是,土衛(wèi)六時太陽系除地球外一顆擁有表面液態(tài)物質(zhì)的星球,卡西尼探測器發(fā)現(xiàn)了土衛(wèi)六上的湖泊和河流,甚至在土衛(wèi)六的極地地區(qū),科學(xué)家還發(fā)現(xiàn)的湖泊。   Read more:   http://www.wired.com/2011/12/titan-lakes-rivers/?pid=2741   3. Kepler452b (2015年) 『地球2.0』 相似度98% 最新托福聽力真題背景知識:宇宙中的宜居星球   This world, whose discovery was announced last month, is the most Earth-like planet found so far, NASA officials say. Its parent star is very similar to our sun, and the planet orbits in the habitable zone. At 1.6 times the size of Earth, Kepler-452b has a “better than even chance” of being rocky, its discoverers have said. Kepler-452b resides 1,400 light-years from Earth.   開普勒-452b是于上個月發(fā)現(xiàn)的,NASA官方表示:迄今為止,該行星是最為類似地球的行星。開普勒-452b的主行星跟我們的太陽非常相像,而且該行星也在宜居帶上做環(huán)繞運(yùn)動。該行星的發(fā)現(xiàn)者們稱:開普勒-452b為地球大小的1.6倍,跟以往任何星球相比,更有可能是巖石行星。開普勒-452b距離地球1,400光年。   Read more:   http://news.ifeng.com/a/20150724/44235252_0.shtml   Reference:   1. https://en.wikipedia.org/wiki/Mars#Surface_geology   2. https://en.wikipedia.org/wiki/Geological_history_of_Mars   3. https://en.wikipedia.org/wiki/Noachian   4. https://en.wikipedia.org/wiki/Water_on_Mars#Middle_to_late_Noachian_.284.1_to_3.8_