用英語寫一篇文章介紹宇宙
宇宙的起源和早期演化是人類文明肇始以來不斷探尋的重要課題,也是人類文明發展的一個原始和持久的推動力。下面是本站小編帶來的用英語介紹宇宙的文章，歡迎閱讀!
用英語寫一篇文章介紹宇宙1
科學家認爲火星衛星形成於火星大碰撞
Mars is a planet of outsized splendor. Despite being only half as big and a tenth as heavy asEarth, it bears the solar system’s tallest mountain, longest canyon and largest crater. At 22and 12 kilometers wide, however, its inner moon Phobos and outer moon Deimos arefigurative small potatoes. Scientists suspect both formed much as Earth’s single large moondid, from a massive debris disk ejected into orbit by a giant impact eons ago. But if Mars’smoons formed like Earth’s, why are they so very much smaller?
The answer may be that they did not form alone. New simulations from Pascal Rosenblatt of theRoyal Observatory of Belgium and colleagues show how the debris disk from a giant impact onMars could have generated additional moons a few hundreds of kilometers in size. Afterforming in the dense inner regions of the disk, those larger moons would have stirred the disk’ssparser outer reaches, allowing smaller companions like Phobos and Deimos to coalesce fromthe ripples. The study appears in the journal Nature Geoscience.
In this scenario, the reason we only see Phobos and Deimos today is that the bigger moonswere destroyed a few million years after their formation. Their low, fast orbits outpaced Mars’srotation, creating a tidal pull that sent them spiraling down to crash into the planet (Earth’smoon, by contrast, orbited slower than our planet’s rotation, allowing it to spiral outwardand survive). Future investigations could test the new hypothesis by looking for clusters ofMartian craters produced by the infalling moons, but in the meantime, proof that Mars can killits companions is right before our eyes: The orbit of Deimos is stable, but Phobos is in a deathspiral, losing two centimeters of altitude per year to Mars’s tidal pull. It will plunge into theplanet in 20 million to 40 million years, leaving lonely, far-out Deimos as the last vestige ofwhat may have been a once-mighty system of Martian moons.
用英語寫一篇文章介紹宇宙2
恆星揭示隱藏星系所在
Four stars near the bright band of the Milky Way have revealed a secret:
the presence of a hidden dwarf galaxy.
Six years ago astronomers predicted that such a galaxy might be in that region based on observed ripples in the Milky Way's disk.
The galaxy is small, faint, and dominated by invisible dark matter.
That combination obviously makes it very hard to see.
Furthermore, it lies behind a shroud of dust that blocks any visible light from passing through.
Now scientists have identified four stars that appear to belong to the galaxy by examining infrared light, which can cut through dust.
The stars are known as Cepheid variables.
They pulse brighter and dimmer in a predictable pattern, which allows astronomers to determine how far they are from us—about 300,000 light years.
That distance puts them well beyond the main body of the Milky Way and right where an orbiting dwarf galaxy might lie.
The finding is in the Astrophysical Journal Letters.
Dwarf galaxies like this one are thought to contain more dark matter than regular matter.
So tracking down such dwarfs could give researchers more clues in the quest to figure out what dark matter is made of.
銀河系亮帶附近的4顆恆星揭示了一個重大祕密：
那就是一個隱藏矮星系的存在。
天文學家們曾在6年前根據銀河系盤面觀察到的漣漪推斷該區域可能存在一個星系。
他們推斷這是個很小且很微弱的星系，而且主要是由不可見的暗物質組成。
這樣特徵的星系大大增加了觀測難度。
此外在它前面還有一層阻隔任何可見光線通過的塵埃。
而現在科學家們通過檢測可穿透塵埃的紅外線已經發現了4顆似乎屬於這個星系的恆星。
這些恆星就是我們熟知的造父變星。
在一種可預測的模式中，它們一亮一暗的節奏使得天文學家能夠確定它們距離我們究竟有多遠—約30萬光年。
這樣的距離使它們遠於銀河系主體，正好位於一個矮星系軌道的所在。
這一發現已經在《天體物理學》雜誌上發表。
像這樣的矮星系含有的暗物質比普通物質要多。
所以追蹤這種矮星系能爲研?a href="">咳嗽毖芯堪滴鎦實淖槌商峁└嘞咚鰲?/p>
用英語寫一篇文章介紹宇宙3
夏威夷大學定義超星系團蘭天
We finally know our cosmic address.
我們終於搞清楚了宇宙的所在。
For the first time, astronomers have identified our home supercluster—a conglomeration of groups of galaxies and larger clusters of galaxies, all interconnected in a stringy web.
天文學家第一次發現了我們的宇宙家園超星系團，這是星系團和較大星系羣的一種聚集體，其中所有星系都是相互聯繫的網絡。
Researchers, led by an astronomer at the University of Hawaii at Manoa, have named this supercluster Laniakea, which means “immense heaven” in Hawaiian.
在夏威夷馬諾亞大學一位天文學家領導下的研究人員們將此超星系團命名爲蘭天，夏威夷語意思是“廣袤無垠的天堂”。
Laniakea encompasses 100,000 galaxies stretched out over 500 million light-years.
蘭天超星系團內部包含10萬個星系，延伸5億光年的距離。
Our own Milky Way is just one of these.
我們的銀河星系就是其中一個星系。
The study is in the journal Nature.
這項研究已經在《自然》雜誌上發表。
Superclusters are some of the universe's largest structures, and have boundaries that are tough to define—especially from inside one.
超星系團是宇宙中最大的組織結構，並且很難定義各個星系團的邊界，尤其是內部的星系。
The team used radio telescopes to map out the motions of a large collection of local galaxies.
這個研究小組使用電波望遠鏡在地圖上標出大量局域星系團的運動。
Within a given supercluster, all galaxy motions will be directed inward, toward the center of mass.
而在超星系團內部，所有星系都是向內部質心運動。
In the case of Laniakea, this gravitational focal point is called the Great Attractor, and influences the motions of our Local Group of galaxies and all others throughout our supercluster.
至於蘭天，其重力焦點被稱爲巨引力源並且影響着我們局域星系的運動，所有的其他星系都是穿過我們的超星系團。
It's time to update our intergalactic maps: Laniakea is home sweet home.
現在應該更新我們的星際地圖:蘭天就是我們的美好家園。
研究發現仙女座星系質量幾乎是銀河系兩倍
How heavy is the Milky Way in comparison to its neighbor galaxy, Andromeda?
和鄰居仙女座相比，我們的銀河系到底有多大?
Well, depends how you calculate it.
好吧，這就要看你如何計算。
In 2006 one group of astronomers figured the Milky Way was twice as massive as Andromeda.
2006年一組天文學家指出銀河系的質量是仙女座的2倍。
A 2009 estimate evened the score, calculating that the two galaxies are equal in mass.
而2009年的結論則表示二者質量持平。
Now a new formula suggests we're only half the mass of Andromeda.
現在的最新結論得出我們只有仙女座星系的一半。
To come up with that number, astronomers first measured the speed and distance of galaxiesbetween three and 10 million light-years away.
這個數字是天文學家們首次根據3百萬到一千萬光年之間的星系的速度和距離所得出。
That allowed them to calculate the deformation of spacetime, and thus the mass, of ourstellar neighborhood, aka the Local Group—a group of more than 50 galaxies, in which theMilky Way and Andromeda dominate.
這些數據可以計算出時空彎曲的程度，從而也可得出我們鄰居，一個含有50個星系以上被稱爲本星系羣的質量大小，我們銀河系和仙女座都包含在這個星系羣中。
They deduced the center of mass between the two heavyweights and found that Andromedamay indeed be twice as massive as the Milky Way.
他們根據二者的重量級推導出質心，然後發現仙女座也許真的是銀河系的2倍。
The results are in the Monthly Notices of the Royal Astronomical Society.
這項研究結果已在《皇家天文協會每月通告》雜誌上發表。
The researchers say this new model might be more accurate than past ones, because itaccounts for dark matter far from each galaxy's center—assuming the data's right, that is.
研究人員表示這種新的模型也許比之前那些都精確，因爲它是根據遠離每個星系中心的暗物質計算—假設這些數據都正確，那就是正確的。
"Well, I never bet money on anything.
是的，我從來不爲任何事情打賭。
Because I'm aware of all the uncertainties and approximations."
因爲我會意識到所有不確定和大概的情況。
Lead author Jorge Penarrubia of the University of Edinburgh.
這項研究的首席作家愛丁堡大學的喬治佩娜拉比亞這樣說道。
"One year from now, two years from now, some clever guy will come and say, ‘Hey, you forgotto include this, actually when you do everything changes,’ and then you will have to acceptthat."
從現在起的1年，2年，有些自以爲聰明的傢伙也許會出現：嘿，你忘記將這個算在內，實際上，當你已經開始，任何事情都在變。然後你就不得不接受。
For now, we'll just have to accept that we live in the wimpier of the two galaxies.
從現在開始，我們將不得不接受我們居住在這兩個星系中的那個較小的一個上面。
At least until the next weigh-in.
至少，直到下一次有人比重前只能接受現在的結果。
