[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]當(dāng)世界末日來(lái)臨時(shí)我們將知道該去責(zé)備什么。科學(xué)家們已發(fā)現(xiàn)明顯的跡象表明：太陽(yáng)有一個(gè)小弟弟，它是一顆暗星，其偏心軌道導(dǎo)致彗星群和流星雨周期性降落地球。 

    [2]這顆被天文學(xué)家叫做復(fù)仇女神星的暗星被認(rèn)為是一顆"褐矮星"，它圍繞太陽(yáng)旋轉(zhuǎn)的軌道大得要用光年計(jì)量，光年是光在一年中走過(guò)的距離，大約等于 6萬(wàn)億英里。

    [3]研究表明，每經(jīng)過(guò)2600萬(wàn)年，這顆星的偏心軌道就將它帶到距太陽(yáng)系1光年的范圍內(nèi)。在那里，它引起了奧爾特云的浩劫，奧爾特云是一個(gè)巨大的圍繞太陽(yáng)系的區(qū)域，里面包含了數(shù)十億從行星形成中分離出來(lái)的宇宙碎塊。

    [4]它每一次訪問(wèn)太陽(yáng)系時(shí)，都從軌道上甩出上百萬(wàn)個(gè)巖塊，其中一些飛向地球的方向--有幾次幾乎摧毀地球上的生命。

    [5]天文學(xué)家長(zhǎng)期以來(lái)一直懷疑太陽(yáng)是否有一個(gè)小伴星。最近，兩個(gè)獨(dú)立的研究小組已經(jīng)發(fā)現(xiàn)了一些端倪。