2016-04-01

English

http://www.chinavoa.com/show-8469-236117-1.html

Space "Treasure Map" Guides E.T. Search

宇宙藏宝图

Carl Sagan once referred to our home planet as [CLIP: "a mote of dust suspended in a sunbeam."] And that poetic description holds true for a lot of exoplanets, too. In fact one of the simplest ways we detect exoplanets is by looking at their sunbeam… and measuring how it dims, ever so slightly, as the exoplanet passes across it, called a transit.

卡尔·萨根曾经这样描述我们居住的地球：阳光普照下的一颗微小尘埃。而这种诗情画意的描述对很多外星球来说也是适用的。实际上，我们探测外星球的一个简单方法就是通过观察它们的反射光，并且测量光线的衰减情况。随着外星球运动，外星球的反射光路过太阳的时候会衰减，即使有时候衰减很弱，这种现象被称为凌。

Which raises an interesting question: "Thinking about extraterrestrial observers—which of them would observe the Earth, moving across our own sun?" Ralph Pudritz, a theoretical astrophysicist at McMaster University in Canada. He and his colleague René Heller quantified the narrow band of space from which any observers on other worlds would be able to see the Earth transiting the sun.

这就引发了一个有趣的问题: 考虑一下地外观测器——可以用来观测地球，那么当我们穿过太阳的时候呢?这是Ralph Pudritz，加拿大McMaster 大学的天体物理学家。他和他的同事 René Heller测量了一下在其它宇宙上可以看到地球凌日侍的任何一个观测器到地球之间的狭长带的距离。

And they determined that this line of sight would be a plane just half a degree thick, but that cuts through a slice of our galaxy that's estimated to contain 100,000 sunlike stars… along with their companion planets. The analysis is in the journal Astrobiology.

他们确认了这条狭长带为一个只有半度厚的平面结构，但是却可以使得像是含有100000个太阳般大小的恒星所在的我们这种银河系的一部分光线通过， 连同发出光线的星球。该研究分析已经发表在《天体生物学》杂志上。

Pudritz and Heller suggest that hunters of extraterrestrial life may want to listen particularly closely for signals originating at star systems within that narrow band of galactic sky. Advanced civilizations there may have already detected us using the transit method, they say, and may now be sending us a message. You might think of this paper, then, like a treasure map, for intelligent life. "We don't know if there's treasure out there of course, right? You never know that about a treasure map. But it's a good place to look.”

Pudritz 和 Heller 建议，搜寻地外生命体也许需要特别密切注意在一个狭长的星级空间带中的一个恒星系统发出的原始信号。高等文明也许已经用这种凌日的方法发现了我们的存在，他们说，也许现在这些高等文明正在给我们发信息呢。你也许想看看这片文章，想看一个藏宝图一样，寻找智能生命体 。我们当然不知道是否有宝藏，对吧?你从来没见过那个藏宝图，但是去参观一下也不错。