太阳隐藏着的小兄弟威胁着地球

Suns Hidden Twin Stalks Planet Earth

太阳隐藏着的小兄弟威胁着地球

[1] When the end of the world comes, we'll know what to blame. Scientists have found compelling evidence that the Sun has a baby brother, a dark star whose eccentric orbit is responsible for periodically showering the Earth with comets and meteorites.

[2] The dark star--named Nemesis by astronomers--is thought to be a brown dwarf" that spins round the Sun in an orbit so large it is measured in light years, the distance light travels in a year, equivalent to about 6,000 billion miles.

[3] The research suggests that, every 26m years, the star's eccentric orbit brings it within one light year of the solar system. There it causes havoc in the Oort Cloud, a huge region surrounding the solar system that contains billions of bits of cosmic rubble left over from the formation of planets.

[4] Of the millions of rocks it throws out of orbit at each visit, some hurtle Earthwards--and have several times nearly wiped out life on Earth.

[5] Astronomers have long wondered if the Sun has a smaller partner. Recently, two independent groups of researchers have found evidence of one.

[1]当世界末日来临时我们将知道该去责备什么。科学家们已发现明显的迹象表明：太阳有一个小弟弟，它是一颗暗星，其偏心轨道导致彗星群和流星雨周期性降落地球。

[2]这颗被天文学家叫做复仇女神星的暗星被认为是一颗"褐矮星"，它围绕太阳旋转的轨道大得要用光年计量，光年是光在一年中走过的距离，大约等于 6万亿英里。

[3]研究表明，每经过2600万年，这颗星的偏心轨道就将它带到距太阳系1光年的范围内。在那里，它引起了奥尔特云的浩劫，奥尔特云是一个巨大的围绕太阳系的区域，里面包含了数十亿从行星形成中分离出来的宇宙碎块。

[4]它每一次访问太阳系时，都从轨道上甩出上百万个岩块，其中一些飞向地球的方向--有几次几乎摧毁地球上的生命。

[5]天文学家长期以来一直怀疑太阳是否有一个小伴星。最近，两个独立的研究小组已经发现了一些端倪。#p#

[6] One group, led by John Matese, professor of physics at the University of Louisiana at Lafayette, confirms the notion that it is most likely to be a brown dwarf, a star that never accumulated enough mass to ignite and which has simply sat in space smouldering for billions of years.

[7] Matese studied 82 comets from the Oort Cloud and found common elements in the shape of their orbits that could only be explained if they had been influenced by the gravitational pull of an object several times the size of Jupiter and existing about 25,000 times farther from the Sun than the Earth.

[8] Matese said: "A companion to the Sun orbiting at these distances would have little effect on the planets. But it would play a big role in the way comets ' made their way' from their birth places in the planetary disc out to the Oort Cloud and on now they can return to the inner solar system."

[9] Further research was published by Richard Muller, professor of physics at the University of California, Berkeley, following analyses of moon rock samples brought back to Earth by Apollo 14.

[10] The absence of a protective atmosphere means the moon has been subjected to intense bombardment in its 4.5 billion-year existence.

[6]一个由拉斐特的路易斯安娜大学物理学教授约翰·马泰塞领导的小组证实了一个想法，那就是它最有可能是一颗褐矮星，这是一种永远也不能积聚足够的质量着火燃烧的星，它只是在太空中数十亿年地无焰闷烧。

[7]马泰塞研究了来自奥尔特云的82颗彗星，发现在它们轨道的形状上有共同的因素，那只有在它们是被一个数倍大于木星的天体的引力作用所影响，且这个天体距太阳的距离比地球要远25，0000倍的情况下才能解释。

[8]马泰塞说："一个离太阳如此遥远的伴星对行星的影响是微乎其微的。但是，在彗星从它们在行星盘的诞生地'前进'到奥尔特云的方式上，以及它们能返回太阳系内部的途径上，这颗星扮演着重要的角色。"

[9]加州大学伯克利分校的
物理学教授理查德·马勒在分析了"阿波罗14号"带回的月球岩石标本之后，公布了进一步的研究成果。

[10]由于缺乏大气的保护，月球在它存在的45亿年间遭受了强烈的撞击。

[11] Muller's breakthrough was to find a way to date" how long ago any particle was melted--meaning he could build up a picture of whether the moon gets a constant barrage or suffers spells of intense bombardment.

[12] He said; "The evidence clearly shows that the moon has gone through spells of relatively frequent impacts and others of reduced intensity. I believe it is likely that this is because the Oort Cloud is being disturbed by a massive body that is throwing comets out of stable orbits, a small fraction of which could reach the Earth."

[13] Muller and others believe that the dark star probably takes about 26m years to complete an orbit around the sun.

[14] Other scientists have already noted that mass extinctions of life on Earth seem to occur in a pattern with gaps equivalent to multiples of 26m, suggesting some regular event is causing the comets to come Earth's way.

[15] The best-known such event was the one that wiped out the dinosaurs 65m years ago, but that was not the worst; the planet has suffered several such large mass extinctions

[16] Astronomers have found the first Earth-sized planet orbiting another star. The discovery raises the chances of finding planets that could support life as we know it.

[11]马勒的突破是他找到了一种确定粒子被融化的年代的方法，这意味着他可以确立这样一幅画面，即月球是受到接二连三的轰击还是经历了间歇性的强烈的粒子辐射。

[12]他说："有迹象清楚表明，月球经历了比较频繁的撞击，以及其它强度减少的撞击。我认为这可能是由于奥尔特云受到一个正在把彗星抛出稳定轨道的大天体的扰动，其中一小部分彗星可能会到达地球。"

[13]马勒和其他一些人认为，这颗暗星绕太阳运行一周大约要用2600万年的时间。

[14]另一些科学家已经注意到，地球生物的物种灭绝现象出现的间隔是2600万的倍数，这说明了某个规律性事件造成彗星降临在地球上。

[15]这类事件中最著名的一个就是6500万年前恐龙的灭绝，但这还不是最坏的；这个星球已经经历了几次如此大规模的灭绝。