White House Adviser: US Must Prepare for Asteroid
Updated: 4 days 14 hours ago
Lee Speigel
Translation by Autumnson Blog
(Oct. 25) -- If an asteroid were on a collision course with Earth, would we be ready to defend against its destructive impact or would we be helpless and defenseless?
(10月25日) - 如果一顆小行星在撞擊地球的航程上,我們會是準備好防衛它的破壞性撞擊,抑或我們將是無助和全無防衛?
NASA, America's space agency, is being charged with leading the way to protect not only the U.S. but the entire world in the event of such a horrifying scenario. And a top White House science adviser says we have to be prepared.
美國航天機構美國航天局,正被指控帶頭保護不僅美國、且是整個世界,在這樣一個恐怖場景的事件,而一位白宮科學顧問說我們要有所準備。
In separate 10-page letters to the House Committee on Science and Technology and the Senate Committee on Commerce, Science and Transportation, John Holdren, director of the White House Office of Science and Technology Policy, or OSTP, outlines plans for "(A) protecting the United States from a near-Earth object that is expected to collide with Earth; and (B) implementing a deflection campaign, in consultation with international bodies, should one be necessary."
在另外的10頁給內務委員會科學和技術委員會和參議院商務、科學和運輸委員會的信件,白宮辦公室科學和技術政策,或OSTP,的主任約翰霍爾德倫,概述計劃“(一)保護美國免遭預計將與地球相撞的近地球物體;及(二)實施一偏斜運動,與國際機構進行磋商,如果是需要的。“
The White House has asked Congress to consider how to best deal with the potential threat to Earth of an impact with an asteroid from space
白宮已要求國會考慮如何最好地應付,來自太空的小行星對地球撞擊的潛在威脅
While Holdren indicates that no large asteroid or comet presents an immediate hazard to our planet, the fact that devastating impacts have occurred on Earth in the distant past is enough to warrant safety precautions for the future.
雖然霍爾德里指出沒有大的小行星或彗星,對我們的星球呈現一即時危害,事實上破壞性的影響已曾在遙遠的過去發生在地球上,就足以保證為未來作安全防範。
"Indeed, a steady stream of these objects enters the Earth's atmosphere on a daily basis, consisting mostly of dust-sized particles and estimated to total some 50 to 150 tons each day," Holdren wrote.
事實上,這些物體每天源源不絕進入地球大氣層,包括主要是塵埃粒子大小的,和估計每天大約共有50至150噸的,”霍爾德倫說。
As remote as it may seem that Earth could be the target of a giant rock from space, nevertheless, Holdren insists that "the possibility of a future collision involving a more hazardous object should not be ignored."
它可能看起來有咁遠得咁遠,地球可能是來自太空的巨大岩石目標,不過,霍爾德倫堅持“一次未來的可能碰撞涉及一更危險的物體,是不應該被忽視的。”
Asteroids are rocky bodies found within the inner solar system, originating in an area known as the asteroid belt, located between the planets Mars and Jupiter.
小行星是岩石體發現於太陽系內部,來自一個地區被稱為小行星帶,位於火星和木星之間。
If a large asteroid were to strike Earth, it could cause a global climate change, which many scientists believe is what caused the extinction of the dinosaurs more than 60 million years ago -- not a good prospect for life on Earth in the present day if a similar event occurred.
如果一顆大的小行星要襲擊地球,它可能導致全球氣候轉變,那許多科學家相信是60多萬年前導致恐龍滅絕的原因 - 如果類似的事件發生,對於目前在地球上的生命,不會是一良好的前景。
NASA's Near Earth Object program, or NEO, looks for and monitors asteroids that are at least a kilometer in diameter.
But, as Holdren points out, one problem in the search is that "the orbits of known objects can be changed by gravitational or solar radiation perturbations, or even collisions with other objects, meaning that periodic monitoring of known NEOs must also be conducted."
Numerous movies have depicted the devastation caused by an asteroid collision with Earth, including "Meteor" (1979), "Deep Impact" (1998) and "Armageddon" (1998).
After 12 years of cosmic hunting, NASA search teams have determined that 149 NEOs larger than a kilometer in size are in orbits that might pose a problem for Earth, but none is considered an impact threat in the next 100 years.
Asteroid hits Earth Animation
小行星襲擊地球動畫
西元2007年08月03日
The White House OSTP office is working to establish plans and procedures in the event of a possible NEO threat to America.
One of those plans involves using the Federal Emergency Management Agency, in the Department of Homeland Security, to handle responsibilities on the ground regarding an NEO threat.
After an asteroid-to-Earth trajectory is determined to impact an area of the U.S., FEMA would notify the population through the National Warning System and it would begin emergency response activities.
Holdren's letter also indicates the importance of notifying other countries of an impending asteroid strike "in an effort to minimize the potential loss of life and property."
And there's the hope that, if an asteroid becomes an actual threat to our planet, a plan would be implemented to try to somehow either destroy the rock or deflect it off course.
Holdren suggests to Congress that NASA and the Department of Defense should work together to devise any strategy that would involve the military.
So the good news is that high-level discussions are on the plate as to how Earth can defend itself against the onslaught of a potential disaster from space.
The bad news: There's no plan set up yet. For the time being, we're staying out of harm's way.
壞消息:仍沒有計劃訂立。目前,我們逗留在傷害的路外面。
Here is the entire text of Holdren's letter to Congress.
http://www.aolnews.com/weird-news/article/white-house-adviser-us-must-prepare-for-asteroid/19687765
美國太空總署指出地球附近小行星複雜性遠超出之前預計
發表於 2010-9-4 01:19
目前,美國太空總署斯皮策太空望遠鏡對近地小行星的最新勘測統計顯示,地球附近的小行星的多樣複雜性遠超出之前的預計,一些太空岩石發光明亮,而另一些則昏暗、光綫不清楚。這 項發現表明近地小行星各式各樣,遠超出科學家最初的評估。據悉,科學家通過美國太空總署斯皮策太空望遠鏡對100顆太空岩石小行星進行紅外綫觀測得出這一結 論。美國北亞利桑那州大學的大衛-特裏林(David Trilling)是此項研究負責人,他說:“這些太空岩石告訴我們它們的起源,這就像研究河床中的鵝卵石可洞悉這些石塊如何從山脉上分離出來。”
小行星數量普查
這一最新發現是斯皮策望遠鏡測量700多顆近地天體統計特徵計劃的一部分,這項研究結果已發表在9月刊的《天文學雜志》上。
斯皮策太空望遠鏡紅外觀測可幫助天文學家收集更多關于小行星構成成分和體積大小的精確評估,而不僅僅局限于這些小行星是否發光。在可見光觀測下,小行星很被區分是否是較大昏暗的、或者是較小光亮的太空岩石。因爲這兩者在可見光下反射光綫狀况是一樣的。
紅外綫觀測數據可提供真實的小行星溫度,從而告訴天文學家小行星關于實際大小和構成的信息。較大昏暗的太空岩石比較小光亮的太空岩石具有更高的溫度,這是因爲它們可以吸收更多的陽光。
目前,特裏林和研究小組同事對100顆近地小行星進行了初步分析,他們計劃明年觀測600多顆近地小行星。現估計近地小行星的數量大約爲7000顆,遠超過之前的預計。特裏林說:“我們很少知道近地小行星數量的物理性參數,我們的研究數據將告訴我們更多的關于近地小行星的數量,以及它們如何演變。這些數據對于未來研究近地天體的太空任務十分有益。”據悉,美國太空總署最新太空計劃是2025年發射載人航天器登陸小行星。
小行星的構成成分
研究人員稱,斯皮策太空望遠鏡觀測顯示一些較小的近地天體具有令人驚奇高的反照率。由于暴露于太陽輻射下,小行星表面逐漸變得昏暗,那些光亮表面的小行星表明它們形成時間不長,是年輕的小行星。他們强調指出,這是近地小行星數量繼續變化的可靠證據。
此外,迄今小行星觀測數據證實其具有很大的差异性,遠超過之前科學家的估計,這暗示著它們可能存在著不同的起源方式。一些小行星可能來自火星和木星之間的主小行星帶,而另一些小行星則可能來自太陽系其它區域。
小行星的多樣性暗示著它們的成分非常複雜,這就像太陽系形成之初的混沌狀態。未來斯皮策望遠鏡和美國太空總署廣域紅外勘測探測器將揭示更多關于近地小行星的秘 密,告訴我們這些小行星的成分構成。幷提供宇宙天體如何分布在地球附近,以及它們所存在的水分子和有機分子如何爲孕育生命提供條件。
http://www.e-zone.com.hk/discuz/viewthread.php?tid=21839&extra=page%3D1
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