Dark matter is that mysterious stuff that apparently accounts for some quarter of the mass and energy in the universe.
暗物质是一种神奇的材料,它显然在宇宙中的质量和能量中占据很大的一部分。
And for one small wannabe-galaxy, dark matter may have been a lifesaver.
而对于小瓦纳比星系而言,暗物质也许成为了救星。
It's called the Smith Cloud.
它被称为史密斯云。
Astronomers think it's a failed dwarf galaxy that lacked the requisite mass to produce stars.
天文学家们认为它是缺乏必要存在物而不能产生新星的已经衰败的矮星星系。
Many millions of years ago the cloud seems to have collided with the Milky Way and passed through the disk of our galaxy.
数百万年前,这团云物质似乎已经同银河相撞并且穿过我们太阳系的盘状空间。
A new computer simulation finds that the cloud should have been ripped to shreds.
一项新型的计算机模拟研究发现该云团本应该已经粉身碎骨。
That it survived is evidence that it's protected—by a shell of dark matter.
但现有证据表明它是被一层暗物质包裹保护所以仍然存在。
The report will appear in the journal Monthly Notices of the Royal Astronomical Society.
该研究报告将在《皇家天文协会月刊》上发表。
That dark matter shell could have insulated the Smith Cloud from the Milky Way's gravitational forces, which otherwise should have torn Smith apart.
这层暗物质保护壳将史密斯云与来自于银河的重力引力隔绝,否则这道引力势必会撕裂前者。
As if its first fender-bender with the Milky Way wasn't enough, the Smith Cloud is coming back for more.
仿佛第一道屏障弯曲并不足以阻挡银河的重力引力,因此史密斯云正在被吸引过来。
It's on course to slam into our galaxy again—in about 30 million years.
它正处于再次撞向银河系的进程当中—貌似还有3亿年的时间。
Perhaps future astronomers will note whether its dark matter shroud once again saves the cloud.
或许未来天文学家们会发现暗物质是否将再次包裹它再次幸免于难。