http://goo.gl/pJJ7oG 冥王星有多大？新視野號總結長達幾十年的爭論 NASA’s New Horizons mission has answered one of the most basic questions about Pluto—its size. NASA的新視野號任務已能回答關於冥王星最基本的問題之一：它的大小。 Mission scientists have found Pluto to be 1,473 miles (2,370 kilometers) in diameter, somewhat larger than many prior estimates. Images acquired with the Long Range Reconnaissance Imager (LORRI) were used to make this determination. This result confirms what was already suspected: Pluto is larger than all other known solar system objects beyond the orbit of Neptune. 此任務科學家們發現冥王星是1473英里（2370公里），直徑比許多現有的估計更大些。 遠距離偵察成像儀（LORRI）獲得的圖像已被用來進行這個確認。這一結果證實了以往的 猜測：冥王星比海王星以外的軌道所有其他已知的太陽系天體較大。 註：不過鬩神星(Eris)不是估計比冥王星大些嗎(直徑約2400 KM)？2006年冥王星被降成 矮行星，Eris的發現佔了其中一個原因。 “The size of Pluto has been debated since its discovery in 1930. We are excited to finally lay this question to rest,” said mission scientist Bill McKinnon, Washington University, St. Louis. 「冥王星的大小自1930年發現後已爭論不停，我們很高興終於讓這個問題能停止。」 任務科學家 Bill McKinnon 表示 (華盛頓大學聖路易斯)。 Pluto’s newly estimated size means that its density is slightly lower than previously thought, and the fraction of ice in its interior is slightly higher. Also, the lowest layer of Pluto’s atmosphere, called the troposphere, is shallower than previously believed. 冥王星新估算的大小意味著它的密度比以前認為的略低、與冰在其內部的比例略高。另外 ，冥王星的大氣，稱為對流層的最底層，比以前認為的還淺。 Measuring Pluto’s size has been a decades-long challenge due to complicating factors from its atmosphere. Its largest moon Charon lacks a substantial atmosphere, and its diameter was easier to determine using ground-based telescopes. New Horizons observations of Charon confirm previous estimates of 751 miles (1208 km) kilometers) across 測量冥王星的大小一直是一個長達數十年的挑戰，因為它的大氣複雜的因素。其最大的 衛星凱倫缺乏實質的大氣層，它的直徑是更容易使用地面望遠鏡來確認。新視野號觀察 凱倫確認直徑為751英里（1208公里）超過以前的估計。 ※凱倫(Charon)是羅馬神話的地獄渡船夫，給錢才給渡河。(可參考聖鬥士冥界篇) LORRI has also zoomed in on two of Pluto’s smaller moons, Nix and Hydra. 遠距離偵察成像儀（LORRI）也放大了兩個冥王星較小的衛星，尼克斯和許德拉。 ※尼克斯(Nix)，是希臘神話中代表黑夜的女神。 許德拉(Hydra)，希臘羅馬神話中是守衛地獄的九頭蛇。 尼克斯(Nix)與許德拉(Hydra)，相信是取自新視野號(New Horizons)字母開頭的N與H “We knew from the time we designed our flyby that we would only be able to study the small moons in detail for just a few days before closest approach,” said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado. “Now, deep inside Pluto’s sphere of influence, that time has come.” 「最初規劃飛越任務時就已經知道，我們只有在最靠近冥王星前後的短短幾天的時間內 能仔細研究它的小衛星。」 西南研究所，科羅拉多州博爾德市的新地平線首席研究員Alan Stern表示。 「現在，深入冥王星影響的範圍內，研究其小衛星的時刻已到。」 ※註：這段原本翻得很爛，感謝juotung大提供更優的翻譯！ Nix and Hydra were discovered using the Hubble Space Telescope in 2005. Even to Hubble, they appeared as points of light, and that’s how they looked to New Horizons until the final week of its approach to Pluto. Now, the latest LORRI images show the two diminutive satellites not as pinpoints, but as moons seen well enough to measure their sizes. Nix is estimated to be about 20 miles (about 35 kilometers) across, while Hydra is roughly 30 miles (roughly 45 kilometers) across. These sizes lead mission scientists to conclude that their surfaces are quite bright, possibly due to the presence of ice. 尼克斯和許德拉是用哈伯太空望遠鏡在2005年發現，甚至到哈伯發現時，他們只是一個 光點，他們與新視野號對望，直到靠近冥王星的最後一周。現在，最新的LORRI圖像顯示 兩個身材矮小的衛星沒有精確定位，但衛星能見度足夠來量測它們的大小。尼克斯估計 大約20英里（約35公里）以上，而許拉德是大約30英里（約45公里）以上。這些尺寸導致 任務科學家得出結論，它們的表面很光亮，可能是由於冰的存在。 What about Pluto’s two smallest moons, Kerberos and Styx? Smaller and fainter than Nix and Hydra, they are harder to measure. Mission scientists should be able to determine their sizes with observations New Horizons will make during the flyby and will transmit to Earth at a later date. 那麼冥王星的另外兩個最小的衛星，塞伯拉斯和冥河呢？體積更小，比尼克斯和許拉德 微弱，他們是難以測量的。任務科學家應該較能確定與觀察是新視野號於飛越期間來看 它們的大小和稍後幾天將訊息傳送回到地球。 註：塞伯拉斯(另翻「科伯羅司」（Kerberos）)，即地獄三頭犬(可參考聖鬥士冥界篇)。 冥河(Styx)，字義上就是冥界之河，希臘神話裡面有五條冥河，Styx是誓約之河 神話中對著誓河發誓是非常神聖莊嚴的一件事，一旦違背就會遭到嚴厲的懲罰 另外，與其說是冥王星有五顆衛星，倒不如說是四顆衛星繞行冥王星和凱倫 雙星系統 --

※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 114.42.62.6 ※ 文章網址: https://webptt.com/m.aspx?n=bbs/sky/M.1436890577.A.F7C.html 1推 hoyunxian: 其實希臘神話裡面有五條冥河，Styx是誓約之河 07/15 09:45 了解，我把這字義加上去了，感恩！ 好像是，WIKI也有記錄，那我也註明一下好了，謝謝 多謝，那一段我翻得很怪，馬上修改^^ 推 SWW: 這個系統實在太酷了~~~ 07/16 00:43 感謝提醒，我現在就去改正，3Q ※ 編輯: Js1233 (114.42.60.162), 07/17/2015 21:19:00