科學家呼籲加快搜尋撞地小行星
An international group of astronauts, scientists and others have called for a rapid expansion of efforts to detect asteroids capable of causing widespread destruction on earth, warning that this is one of the biggest threats to humanity in the coming centuries.
一個由宇航員、科學家等人組成的國際團體呼籲儘快加大偵測力度，找出那些能夠對地球造成大面積損害的小行星。該團體警告說，這是未來幾百年內人類面臨的最大威脅之一。
Led by Lord Rees, Britain’s royal astronomer, and Brian May, a PhD in astrophysics as well as guitarist with the rock band Queen, the group said a hundredfold increase in the number of objects detected each year was necessary over the next decade.
這個團體以英國皇家天文學家裏斯勳爵(Lord Rees)和天體物理學哲學博士、皇后樂隊(Queen)吉他手布賴恩•梅(Brian May)爲首。該團體表示，今後十年，有必要把每年發現的天體數增加一百倍。Academic projects to detect and track asteroids that might one day collide with earth have been under way for more than 50 years. The work was boosted in 1998 when Nasa was given a decade to identify near-earth objects with a diameter of more than 1km — a size that would turn a collision into a potentially extinction-level event.
發現和追蹤可能與地球相撞的小行星的學術課題已開展了逾50年。1998年，美國國家航空航天局(NASA)曾被要求在十年內找出直徑大於一公里的近地天體，從而加大了這一工作的執行力度。當天體的直徑大於一公里時，與地球的相撞就有可能導致地球上的生物滅絕事件。
However, astrophysicists warn that asteroids and meteors as small as 50m across could still cause devastation on earth, with a direct hit capable of wiping out a city and killing millions. An undetected meteor estimated to be 20m in diameter entered the atmosphere over Russia last year and exploded at a height of several miles, causing a shockwave that injured 1,500 people (pictured). Even the devastating 1908 impact at Tunguska in Siberia, the largest in human recorded history, was caused by an object of only around 50m, said Lord Rees.
不過，天體物理學家警告說，即使是直徑只有50米的小行星和流星，仍有可能導致地球上的巨大災難，因爲它的直接撞擊能毀滅一個城市並導致數百萬人喪生。去年，一個事先未被發現的、直徑估計爲20米的流星曾進入俄羅斯上空大氣層，並在幾英里高空爆炸，產生的激波曾導致1500人受傷。里斯勳爵表示，人類歷史上有記錄的最大規模撞擊事件是1908年發生在西伯利亞通古斯的災難性撞擊事件，然而即使是導致那次撞擊的天體，直徑也只有大約50米。Only around 1 per cent of the 1m asteroids, meteors and comets that could cause massive damage on earth have been detected so far, according to a declaration by the group issued on Wednesday.
根據該團體週三發佈的聲明，到目前爲止，在可能對地球造成大規模毀壞的1百萬小行星、流星和彗星中，人類已發現的只佔大約1%。“Nasa has done a very good job of finding the very largest objects, the ones that would destroy the human race,” said Ed Lu, an astronaut who flew three trips to the International Space Station. “It’s the ones that would destroy a city or hit the economy for a couple of hundred years that are the problem.”
曾三次登上國際空間站(International Space Station)的宇航員盧傑(Ed Lu)表示：“NASA在發現能毀滅人類的極大天體方面取得了很大成績。現在的問題是那些會毀滅一個城市或導致經濟倒退幾百年的天體。”“The more we learn about asteroid impacts, the clearer it becomes that the human race has been living on borrowed time,” said Mr May, who broke off his academic studies to become a musician but returned to complete his PhD at the University of London’s Imperial College in 2007. The campaign launched this week is intended to raise awareness and put pressure on governments to act, he added.
該團體呼籲人們近期將主要精力放在危險天體的偵測工作上，而不要急於找到毀滅或推開危險天體的手段。盧傑表示，處理將與地球相撞的小行星“相對容易”。他說，發現小行星後，距離未來的相撞可能還有幾十年的準備時間，“提前這麼長時間發現的情況下，人們要做的只是向它們發射飛船而已”。里斯勳爵表示，作爲對NASA地基望遠鏡的補充，要想偵測可能對地球造成毀滅性的打擊的小型天體，可能需要在地球和金星之間飛行的飛船上安裝紅外望遠鏡。
