第1472期:Dangers from outer space

词汇表little green men （比喻）外星人meteorite 陨星、陨石cosmic ray 宇宙射线good old （赞美语气）老牌的、靠谱的a rough ride 一段艰难的历程mass extinction 物种大灭绝to kill off 杀死、消灭crater （火山口式的）圆坑geological 地质的to wipe out 彻底灭绝dense 密度大的to orbit 沿轨道围绕（行星或恒星）运行Solar System 太阳系comet 彗星to hurtle 猛冲to put someone off (something) 丧失对某事的兴致macabre 恐怖的，令人害怕的interstellar 星际的to snuff it （俗语）死亡，断气文稿:What is the greatest threat to life on our planet? Is it climate change? 我们星球上生命面临的最大威胁是什么？是气候变化吗？Shortages of food or water? Or might an altogether bigger danger come from somewhere further away: space?食物或水短缺？或者一个更大的危险可能来自更远的地方：太空？We’re not talking about an invasion by little green men here.我们不是在谈论小绿人的入侵。 Instead, how about the prospect of being hit by a gigantic meteorite, zapped by lethal cosmic rays or fried by the deadly energy of an erupting star?相反，被巨大的陨石击中、被致命的宇宙射线击中或被喷发的恒星的致命能量炸毁的前景如何？It wouldn’t be the first time. Good old planet Earth has had a rough ride over the last 3.7 billion years, with some spectacularly devastating events. 这不会是第一次。在过去的 37 亿年里，古老的地球经历了一段艰难的旅程，发生了一些惊人的毁灭性事件。The most famous mass extinction was 66 million years ago, when it’s widely believed a meteorite killed off the dinosaurs.最著名的大灭绝发生在 6600 万年前，当时人们普遍认为是陨石杀死了恐龙。 A 110-mile-wide crater in Mexico with the same geological age supports this theory.墨西哥一个 110 英里宽、地质年代相同的陨石坑支持了这一理论。Believe it or not, this wasn’t the most brutal episode in our planet’s history. 信不信由你，这不是我们星球历史上最残酷的事件。That was when a staggering 96% of life was wiped out at the end of the Permian period, 252 million years ago. 那是在 2.52 亿年前的二叠纪末期，惊人的 96% 的生命被消灭。Scientists don’t know for sure why this happened, but any potential explanations carry with them the grim possiblity that similar events could happen again.科学家们不确定为什么会发生这种情况，但任何潜在的解释都带有类似事件可能再次发生的严峻可能性。For example, some experts believe that our Sun has a very dense, dim twin star which is too far away to observe directly.例如，一些专家认为我们的太阳有一颗非常密集、昏暗的双星，距离太远而无法直接观察。 This sleeping giant, dubbed the “Death Star”, could distort the paths of orbiting chunks of icy rock and hurl them towards the rest of the Solar System.这个沉睡的巨人，被称为“死星”，可以扭曲冰块的轨道并将它们抛向太阳系的其他部分。Is this what happened 252 million years ago? Or is there instead, perhaps, a distant, ninth planet in our Solar System which pulls in passing comets and sends them hurtling our way?这是2.52亿年前发生的事情吗？或者，我们太阳系中是否有一颗遥远的第九颗行星，它会吸引路过的彗星并让它们飞向我们的方向？If that isn’t enough to put you off your breakfast, then consider what’s happening to our friend, the Sun. 如果这还不足以让您不吃早餐，那么请考虑一下我们的朋友太阳发生了什么事。The star that has given us the warmth to sustain life is gradually turning into a deadly foe.给我们温暖以维持生命的那颗星星正在逐渐变成一个致命的敌人。 Like all stars, it is slowing dying, burning through its energy supplies. 像所有恒星一样，它正在减慢死亡速度，消耗其能量供应。As it does so, it expands, and in about 2 billion years it will have grown so much that the heat will make life on planet Earth unbearable.当它这样做时，它会膨胀，在大约 20 亿年的时间里，它会增长得如此之快，以至于热量将使地球上的生命难以忍受。While all this sounds a little macabre, take comfort from the fact that the chance of being hit by a giant interstellar projectile is incredibly slim, and that 2 billion years is a very long time.虽然这一切听起来有点令人毛骨悚然，但请放心，被巨大的星际弹丸击中的机会非常渺茫，而且 20 亿年是一段很长的时间。And there’s another thing: if the dinosaurs had not snuffed it when they did, it’s extremely unlikely that human beings would have had the chance to evolve at all.还有一件事：如果恐龙没有在它们嗅到它的时候嗅到它，那么人类根本不可能有进化的机会。