英国《每日邮报》11月11日报道，欧洲太空总署预测，美国东部时间11日晚7点，即北京时间12日早8点，一颗曾用于探测地球重力场的卫星将与地球相撞。
Heads up! A 2,000lb satellite will crash to earth at 7pm EST today - but no one knows where it will land
Scientists predict a 2,000lb satellite will break through the earth's atmosphere at 7pm tonight
Gravity field and steady-state Ocean Circulation Explorer, or GOCE, was launched in 2009 to map variations in Earth's gravity
GOCE ran out of xenon fuel October 21 and has been losing altitude since
Most of spacecraft will burn up, but 45 pieces weighing no more than 200lbs each are expected to survive
Scientists do not know where the satellite will land
A 2,000lb satellite is expected to re-enter the Earth's atmosphere within hours.
According to the European Space Agency, the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) will break through the atmosphere and break up by 7pm Sunday (Eastern time).
'The most probable impact ground swath largely runs over ocean and polar regions, as well as uninhabited areas of Australia,' the space agency noted on its website.
'With a very high probability, a re-entry over Europe can be excluded.'
As the whizzing GOCE - or Gravity field and steady-state Ocean Circulation Explorer - descends, scientists are monitoring its movements to determine the landing site and ensure public safety.
Not everyone is as sure as the scientists are that it will land in the oceans that cover 70 per cent of the Earth's surface.
Incoming: Europe's 2,000-pound Gravity field and steady-state Ocean Circulation Explorer, or GOCE, is expected to plummet down to Earth at 7pm - and no knows for sure where exactly its debris is going to touch down
On Saturday, British gaming company Ladbrokes gave FoxNews.com six to four odds it would crash-land in North or South America.
The 1.2-ton, $466million science satellite built by German and Italian engineers was launched in 2009 to map variations in Earth's gravity, and now it is doomed by its force.
Scientists assemble the data into the first detailed global maps of the boundary between the planet's crust and mantle, among other projects.
The arrowhead-shaped GOCE ran out of xenon fuel on October 21 and has been steadily losing altitude since, tugged by Earth's gravity.
The satellite was intended to orbit at 160 miles, but on Saturday morning it hovering at just 105 miles.
With its aerodynamic design featuring wings and tail fins, GOCE has been called the ‘Ferrari of space.’
Most of the spacecraft will burn up as it blasts through the atmosphere, but up 25 per cent of the satellite is expected to survive re-entry and end up somewhere on the planet's surface.
Jeffrey Kluger, senior science and technology editor for Time Magazine, told CBS that earthlings have no cause for panic, but people should be ‘a little bit worried’ about the plunging pile of scorched space debris.
‘Whenever you have one ton of hardware coming down, no one knows where, that's not a good thing,’ he said.
With two-thirds of Earth covered by water and vast areas of sparsely populated land, the risk to human life and property is considered extremely low, the European Space Agency said.
Kluger explained that it is estimated that about 45 pieces of satellite debris, each weighing no more than 200lbs, will breach the atmosphere and land within a footprint of 190 square miles.
‘So a satellite would practically have to be aiming at your house to strike it,’ Kluger wrote in his Friday Time column.
Due to constant changes in Earth's upper atmosphere, scientists cannot yet predict where and when GOCE will re-enter.
Satellites that are too bulky to bring down safely to Earth after they had served their purpose are sometimes boosted into one of the graveyard orbits more than 22,000 miles up, where they can hang around for centuries.
For GOCE, however, it was not a viable option because the satellite only has a small, weak ion engine on board.
The last big satellite to fall back through the atmosphere was Russia's failed Phobos-Grunt Mars probe. The 14-ton spacecraft re-entered in January 2012.
In 2011, NASA's 6.5-ton Upper Atmosphere Research Satellite and Germany's 2.4-ton X-ray ROSAT telescope re-entered.
Heiner Klinkrad, head of the European Space Agency's space debris office in Germany, told the site Spaceflight Now that statistically speaking, it is 250,000 times more likely to win the jackpot in the German lottery than to get hit by a GOCE fragment.
About 100 tons of space debris falls to Earth every year, and so far there have been no reports of injuries of fatalities caused by extra-terrestrial scrap metal.
However, under UN’s Convention on International Liability for Damage Caused by Space Objects created in September of 1972, should a space fragment cause damage upon re-entry, the country that launched the satellite would be held accountable, Fox News reported.
The treaty, which has been ratified by 88 countries as of January 2013, guarantees that the state responsible will pay compensation. In the case of GOCE, the satellite was launched from Russia, so that country would be on the hook for any damage. (dailymail)
相关介绍：
根据欧洲太空总署官网上的消息，虽然目前科学家们并未测算出卫星的具体落点，但撞击范围很可能在澳大利亚中部的无人区到南极之间的区域。并且，科学家们将对该卫星的离心力和降落速度进行实时监测，从而确定它的最终落点以保护公众的安全。
据悉，这颗卫星自重约1.2吨，由德国和意大利的航空人员花费4亿6600万美元制造。2009年，该卫星被成功发射到太空，用以探测地球重力场的变化以及海洋环流。
10月21日，这颗箭头形状的卫星在消耗掉所有的燃料之后开始坠落，并由于受到地球引力的作用，最终坠入地球大气层。据科学家介绍，在卫星坠入大气层的过程中，大部分零部件将被烧毁，只有25%的部分可能保留下来。
欧洲太空总署的首席科学家海纳•科林克瑞德说，“被这颗坠落卫星砸中的几率非常小，就连在德国乐透中头奖的几率也会比被砸中的比率高出25万倍。所以，民众根本无需恐慌。”
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