2013年4月11日 星期四

隕石高空爆炸 險釀大禍

隕石高空爆炸 險釀大禍
2013/04/11
After a Brush With an Asteroid, a Sigh of Relief on Earth【By HENRY FOUNTAIN/陳世欽譯】Using an eclectic mix of crowdsourced video, information from Google Earth and data from nuclear test-ban sensors, scientists have gotten a much more accurate picture of the small asteroid that exploded near the Russian city of Chelyabinsk in February.         asteroid  / ˋæstə͵rɔɪd /   n. 『天文』小行星   But what is most clear is that while Chelyabinsk did not exactly dodge a bullet , the city was fortunate to be only grazed by it. “The people of Chelyabinsk were very lucky,” Dr. Edward Lu, a former astronaut who now leads the B612 Foundation, a private initiative to detect similar asteroids, said in Washington in March. graze /grez/ vi.擦過、掠過   The Russian meteor — which was about 18 meters in diameter and came in undetected at roughly 67,000 kilometers an hour — was almost 24 kilometers high when it blew apart. There were no deaths, and most of the 1,500 injuries were from glass as windows shattered when a shock wave hit the city 88 seconds later.  metero / ˋmitɪɚ /  n.流星、隕星blow apart 炸開來    blow /blo/  vi. 1.吹 2.使爆炸        blow, blew, blown, blowing “If it had detonated closer to the ground, it would have been worse,” said Dr. Margaret Campbell- Brown, a member of a team of researchers at the University of Western Ontario. detonate   / ˋdɛtə͵net /   vi. 使爆炸、使觸發   vt.爆炸、觸發    The Canadian team has calculated that the energy released in the Chelyabinsk explosion was the equivalent of about 440 kilotons of TNT, or about 30 times the power of the Hiroshima nuclear bomb. kiloton / ˋkɪlə͵tʌn /  n.千噸nuclear bomb 核彈   That calculation was made with the help of data from a network of acoustic sensors set up to monitor compliance with the treaty to ban nuclear weapons testing. There are about 45 of the sensors worldwide. acoustic / əˋkustɪk /   adj.1.聽覺的 2.音響的 3.聲學的compliance   / kəmˋplaɪəns / n.1.承諾   2.順從、屈服 Thomas M?tzelburg, a spokesman for the Preparatory Commission for the Comprehensive Nuclear- Test-Ban Treaty Organization, which is based in Vienna, said the explosion was detected by more than 20 of the sensors, including one in Antarctica nearly 16,000 kilometers from Chelyabinsk. spokesman 發言人(男或女皆可用)  With knowledge of the energy and information about how fast the meteor was traveling, researchers were able to calculate the mass of the meteor, about 11,000 metric tons. “It’s all about the kinetic energy of that body,” which is related to its mass and velocity, said Richard P. Binzel, a planetary scientist at the Massachusetts Institute of Technology. “All that kinetic energy has to be released .” planetary  adj.『天文』行星的kinetic  / kɪˋnɛtɪk /   / kaiˋnetik / adj.『物理』運動的、運動引起的 The Canadian researchers have used video images of the meteor’s east-to-west trail above Chelyabinsk to help calculate its trajectory and orbit. Since the explosion occurred in daylight, Dr. Campbell-Brown said they asked a colleague there to take night photographs from the same locations. By superimposing the images of the meteor’s path over the night images containing stars, the researchers should be able to plot the path even more accurately. superimpose  /͵supərɪmˋpoz/  vt.把...放置在上面重疊; 加上去 For now, though, they and other teams, including one from the University of Antioquia in Medellin, Colombia, have established that the meteor originated in the inner part of the asteroid belt, in a regular, harmless orbit around the Sun between Mars and Jupiter. It then circled the Sun every 18 months in a highly eccentric orbit — more than two and a half times the Earth-Sun distance at its farthest — before it smacked into Earth. Jupiter /ˋdʒupətɚ/ n.『天文』木星circle  vt.繞eccentric /  ɪkˋsɛntrɪk /  adj.偏心的、『天文』軌道不正圓的smack  /smæk/   v.捆、打、撞 Dr. Jorge Zuluaga, a member of the Colombian group, said he was inspired by work done soon after the event by Stefan Geens, a blogger in Stockholm. Mr. Geens used several videos to triangulate the path. The video does not show the explosion directly, but rather the shadows of lampposts , which moved like the shadow on a sundial as the fireball crossed the sky. lamppost / ˋlæmp͵post  /  n.街燈柱sundial /ˋsʌn͵daɪəl/  n.日晷  Dr. Zuluaga thinks that eventually it will be possible to reconstruct the rock’s orbit so precisely that researchers may be able to detect it retroactively, by poring over images from sky-surveying telescopes taken the last time it flew near the Earth. “Then we can assign it a name,” he said. The videos that were posted online contributed to a surge in interest in projects to detect asteroids . Dr. Lu said his foundation had seen an increase in donations since the explosion. “It made it more real to folks,” he said. “There’s nothing like a hundred YouTube videos to do that.”


全文網址: 隕石高空爆炸 險釀大禍 - 紐時周報精選 - 線上學習 - udn文教職考 http://mag.udn.com/mag/education/storypage.jsp?f_ART_ID=449740#ixzz2Q93Guqbx
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Using an eclectic mix of crowdsourced video, information from Google Earth and data from nuclear test-ban sensors, scientists have gotten a much more accurate picture of the small asteroid that exploded near the Russian city of Chelyabinsk in February.
今年二月有一顆不大的小行星(編按:進入大氣層後稱為流星或隕石,meteor)在俄羅斯車里雅賓斯克市附近的空中爆炸,科學家把眾網友提供的影像,取自Google Earth的資訊,以及透過禁止核試監控感測器獲得的數據加以綜合整理之後,對於這顆隕石的面貌有了精確許多的認識。
But what is most clear is that while Chelyabinsk did not exactly dodge a bullet , the city was fortunate to be only grazed by it. “The people of Chelyabinsk were very lucky,” Dr. Edward Lu, a former astronaut who now leads the B612 Foundation, a private initiative to detect similar asteroids, said in Washington in March.
而最清楚不過的事實卻是,車里雅賓斯克雖未能完全躲過一枚子彈,卻很幸運的只被它輕輕擦過。前太空人盧傑博士主持的民間計畫612基金專門偵測類似的隕石與小行星。他上個月在華府說:「車里雅賓斯克的市民非常幸運。」
The Russian meteor — which was about 18 meters in diameter and came in undetected at roughly 67,000 kilometers an hour — was almost 24 kilometers high when it blew apart. There were no deaths, and most of the 1,500 injuries were from glass as windows shattered when a shock wave hit the city 88 seconds later.
這顆隕石直徑約18公尺,在未被偵測到的情況下以大約6.7萬公里的時速進入大氣層,爆炸時的高度約24公里。它並未造成任何人員死亡,1500名傷者多是在88秒後出現的震波震撼該市時,因為窗戶碎裂而割傷。
“If it had detonated closer to the ground, it would have been worse,” said Dr. Margaret Campbell- Brown, a member of a team of researchers at the University of Western Ontario.
加拿大西安大略大學一個研究團隊的成員瑪格麗特‧坎貝爾-布朗說:「如果它在距離地面更近的位置爆炸,後果勢必更嚴重。」
The Canadian team has calculated that the energy released in the Chelyabinsk explosion was the equivalent of about 440 kilotons of TNT, or about 30 times the power of the Hiroshima nuclear bomb.
該團隊估計,此次爆炸釋出的能量相當於44萬噸黃色炸藥,是廣島原爆威力的30倍。
That calculation was made with the help of data from a network of acoustic sensors set up to monitor compliance with the treaty to ban nuclear weapons testing. There are about 45 of the sensors worldwide.
科學家是在監控各國是否遵守禁止核試條約的聲學感測器所搜集資訊的協助下,推算出這些結果。約有45個此類感測器部署在全球各地。
Thomas M?tzelburg, a spokesman for the Preparatory Commission for the Comprehensive Nuclear- Test-Ban Treaty Organization, which is based in Vienna, said the explosion was detected by more than 20 of the sensors, including one in Antarctica nearly 16,000 kilometers from Chelyabinsk.
維也納全面禁止核試條約組織籌備委員會發言人穆茨爾柏格表示,其中有20多個感測器測得這次爆炸,其中一個位於距離車里雅賓斯克將近1.6萬公里的南極洲。
With knowledge of the energy and information about how fast the meteor was traveling, researchers were able to calculate the mass of the meteor, about 11,000 metric tons. “It’s all about the kinetic energy of that body,” which is related to its mass and velocity, said Richard P. Binzel, a planetary scientist at the Massachusetts Institute of Technology. “All that kinetic energy has to be released .”
科學家掌握這顆隕石的能量及飛行的速度,進而估算它的質量,大約是1.1萬公噸。麻省理工學院的行星科學家賓塞爾表示,「重點完全在於這個物體」與質量及速度有關的「動能」。他說:「這些動能必須全數釋出。」
The Canadian researchers have used video images of the meteor’s east-to-west trail above Chelyabinsk to help calculate its trajectory and orbit. Since the explosion occurred in daylight, Dr. Campbell-Brown said they asked a colleague there to take night photographs from the same locations. By superimposing the images of the meteor’s path over the night images containing stars, the researchers should be able to plot the path even more accurately.
加拿大科學家利用隕石在車里雅賓斯克空中由東至西的拖曳錄影影像,估算出它的行進路線及運行軌道。坎貝爾-布朗表示,由於爆炸發生在白天,他們委託當地的一名同事拍攝同地點的夜間照片。把隕石飛行軌道的照片與含有天體的夜間影像重疊之後,科學家應該可以更準確標繪隕石的軌道。
For now, though, they and other teams, including one from the University of Antioquia in Medell?n, Colombia, have established that the meteor originated in the inner part of the asteroid belt, in a regular, harmless orbit around the Sun between Mars and Jupiter. It then circled the Sun every 18 months in a highly eccentric orbit — more than two and a half times the Earth-Sun distance at its farthest — before it smacked into Earth.
他們與包括哥倫比亞梅德殷市安提歐其亞大學科學家在內的其他研究團隊認為,隕石來自小行星帶內側,在火星與木星之間沿著太陽四周的一條常態無害軌道運行。它每18個月沿著很不正的圓軌道繞太陽一周(最遠處是地球與太陽距離的2.5倍以上),最後衝進了地球。
Dr. Jorge Zuluaga, a member of the Colombian group, said he was inspired by work done soon after the event by Stefan Geens, a blogger in Stockholm. Mr. Geens used several videos to triangulate the path. The video does not show the explosion directly, but rather the shadows of lampposts , which moved like the shadow on a sundial as the fireball crossed the sky.
哥倫比亞研究團隊成員蘇魯亞加博士表示,斯德哥爾摩部落客金斯在隕石爆炸後立刻做的工作使他得到啟發。金斯以幾部影片為隕石飛行的軌道進行三角測量。影片並未直接顯示爆炸,而是顯示街燈柱的影子。火球劃過天際時,這些陰影有如日晷般移動。
Dr. Zuluaga thinks that eventually it will be possible to reconstruct the rock’s orbit so precisely that researchers may be able to detect it retroactively, by poring over images from sky-surveying telescopes taken the last time it flew near the Earth. “Then we can assign it a name,” he said.
蘇魯亞加認為,科學家終將可以精準重建隕石的軌道;他們可以過濾隕石上一次飛近地球期間,天文望遠鏡拍下的影像,進而回溯建構它的軌道。他說:「屆時,我們就可以為它命名。」
The videos that were posted online contributed to a surge in interest in projects to detect asteroids . Dr. Lu said his foundation had seen an increase in donations since the explosion.
Po在網上的影片引起網友對隕石追蹤計畫的高度興趣。盧傑表示,此次隕石爆炸後,B612基金收到的捐款增加了。
“It made it more real to folks,” he said. “There’s nothing like a hundred YouTube videos to do that.”
他說:「這使隕石更貼近一般大眾。要做到這一點,沒有任何東西比100支YouTube影片更厲害了。」


全文網址: 隕石高空爆炸 險釀大禍 - 紐時周報精選 - 線上學習 - udn文教職考 http://mag.udn.com/mag/education/storypage.jsp?f_ART_ID=449740#ixzz2Q93Yiyvw
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