Unless we spend money to spot and prevent asteroids now, one might crash into Earth and destroy life as we know it, say some scientists.
一些科学家说，除非我们现在花钱去发现和预防小行星，否则有可能会撞上地球，摧毁我们已知的生命。
Asteroids are bigger versions of the meteoroids that race acros s the night sky. Most orbit the sun far from Earth and don't threaten us. But th ere are also thousads whose orbits put them on a collision course with Earth.
小行星是穿越夜空的大号流星。大多数绕着远离地球的太阳运行，不会威胁到我们。但也有成千上万的小行星的轨道会让它们与地球发生碰撞。
Buy 10 million a year for the next 25 years to locate most of the space rocks. By the time we spot a fatal one, the scientists say, we'll have a way to change its course.
现在就购买价值5000万美元的新望远镜。然后在接下来的25年里每年花费1000万美元来定位大多数太空岩石。科学家们说，当我们发现致命的岩石时，我们将有办法改变它的路线。
Some scientists favor pushing asteroids off course with nuclear weapons. But the cost wouldn't be cheap.
一些科学家赞成用核武器推动小行星偏离轨道，但成本并不便宜。
Is it worth it? Two things experts consider when judging any risk are: 1) How likely the event is; and 2) How bad the consequences if the event occurs. Experts think an asteroid big enough to destroy lots of life might strike Earth once every 500, 000 years. Sounds pretty rare-but if one did fall, it would be the end of the world. “If we don't take care of these big asteroids, they'll take care of us,” says one scientist, “It's that simple.”
值得吗？专家在判断任何风险时要考虑两件事：1）事件的可能性有多大；2）如果事件发生，后果有多糟糕。专家认为，一颗足以摧毁大量生命的小行星可能在每50万年撞击地球一次。听起来很罕见，但如果真的发生，那将是世界末日。一位科学家说：“如果我们不关心这些大的小行星，它们就会照顾我们。就这么简单。”
The cure, though, might be worse than the disease. Do we really want fleets of nuclear weapons sitting around on Earth? “The world has less to fear from doomsday rocks than from a great nuclear fleet set against them,” said a New York Times article.
然而，治愈方案可能比疾病本身更糟糕。我们真的希望核武器舰队存在于地球上吗？《纽约时报》的一篇文章说：“世界对世界末日岩石的恐惧要比对一支强大的核舰队的恐惧少”。
