[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。