新浪科技讯北京时间1月6日消息,据国外媒体报道,NASA的詹姆斯·韦伯望远镜目前定于2021年3月发射。而在此之前,该项目经历了年复一年的推迟和数十亿美元的资金投入。尽管浪费了大量时间和资金,但这台望远镜将成为红外波段毋庸置疑的“王者”,让我们得以首次触及宇宙中曾经遥不可及的偏远角落。

NASA's James Webb Telescope is now scheduled to launch in March 2021, foreign media reported on Jan. Before that, the project went through years of delays and billions of dollars in funding. Despite the waste of time and money, the telescope will become the undisputed \"king\" of the infrared band, allowing us to reach the remote corners of the universe for the first time.

  从宇宙诞生后形成的第一批星系、到外星生命存在的可能性,要想进一步了解宇宙万物,斥资约97亿美元的詹姆斯·韦伯望远镜将是我们唯一的希望。

From the first galaxies formed after the birth of the universe to the possibility of extraterrestrial life, the James Webb Telescope, for about $9.7 billion, will be our only hope for a better understanding of everything in the universe.

  尽管詹姆斯·韦伯太空望远镜(简称JWST)被奉为NASA传奇性的哈勃望远镜的“继任者”,但事实并非如此。哈勃主要是一台光学望远镜,能够捕获的光线波长范围与人眼差不多,仅向红外线和紫外线波段稍微扩展了一些。论其本质,哈勃望远镜就像一颗巨大的、在太空轨道上运行的眼球,不断传回令人震惊的图片。而假如你的光觉神经和它一样强大,你自己就可以看见这些惊人的景象。

Although the James Webb Space Telescope (JWST) is regarded as the \"successor\" to NASA's legendary Hubble telescope, this is not the case. Hubble is primarily an optical telescope capable of capturing the same wavelength range as the human eye, extending only slightly to the infrared and ultraviolet wavelengths. In its essence, the Hubble telescope is like a giant, orbiting eyeball that keeps sending back shocking images. And if your sense of light is as powerful as it is, you can see these amazing sights yourself.

  但詹姆斯·韦伯望远镜则不然。它将完全在红外波段内进行观测,几乎不会触及人眼能看到的最“红”的波段。换句话说,它将研究一个对人类而言近乎隐形的宇宙。

But not the James Webb telescope. It will be observed entirely in the infrared band, barely touching the most \"red\" band the human eye can see. In other words, it will study a universe that is almost invisible to humans.

  詹姆斯·韦伯望远镜之所以这样设计,主要原因之一是,从地表开展红外波段观测的难度很大。天文学家要想开展精确观察和测量,必须确保夜空绝对晴朗,但地面上的光污染严重限制了观测条件。

One of the main reasons why the James Webb telescope is designed this way is that infrared observations from the surface are difficult. To make precise observations and measurements, astronomers must ensure that the night sky is absolutely clear, but light pollution on the ground severely limits the conditions.

  而红外光污染更是无处不在,因为任何有温度的物体都会发出红外光。人体可以产生100瓦特的红外辐射。地球本身热量也很高,在红外波段显得明亮夺目。就连望远镜自身在室温下也会发出红外光辐射。

Infrared pollution is more ubiquitous because any object with temperature emits infrared light. The human body can produce infrared radiation of 100 watts. The Earth itself is high in heat and is bright in the infrared. Even the telescope itself emits infrared radiation at room temperature.

  总之,我们从地面上并不是完全不能开展红外天文学观测,只是难度极大。因此,我们选择将詹姆斯·韦伯望远镜放置在太空中。

In short, we are not completely unable to carry out infrared astronomical observations from the ground, but are only extremely difficult. So we chose to place the James Webb telescope in space.

  为避开地球的红外光影响,詹姆斯·韦伯望远镜将在距地球150万公里处运行。尽管远离了地球,但太阳也是个问题。你一定感受过夏季室外灼人的阳光吧,那就是红外辐射。即使距地球数百万公里之遥,太阳的热量仍然不容小觑。

To ward off the effects of Earth's infrared light, the James Webb Telescope will operate 1.5 million kilometres from Earth. Although far from the earth, the sun is also a problem. You must have felt the sun burning outside in the summer. It was infrared radiation. Even millions of kilometers away from Earth, the sun's heat is not to be underestimated.

  为此,红外太空望远镜的设计师们可以采取几种应对方案。最常见的一种便是采用主动冷却系统,使望远镜的温度下降到适宜观测红外波段的水平。这是种好方法,此前也在其它红外太空望远镜中得到了采用。但这也限制了望远镜的工作寿命,因为一旦冷却剂耗尽,天文观测就无法继续进行。

To this end, infrared space telescope designers can take several countermeasures. One of the most common is the use of active cooling systems to reduce the temperature of the telescope to levels suitable for observing the infrared band. This is a good way to use it in other infrared space telescopes. But it also limits the telescope's working life, as astronomical observations cannot continue once the coolant is exhausted.

  因此,詹姆斯·韦伯望远镜将独辟蹊径,配备一把昂贵的巨型“太空伞”。这把“伞”长22米,宽11米,由五层反射率极高的材料制成,每层厚度还不及人类头发的直径。这把巨大的“遮阳伞”将使望远镜始终处于阴影之下,温度不超过零下223摄氏度,正适合在目标红外波段内开展观测。

Therefore, the James Webb telescope will find a way out, equipped with an expensive giant'space umbrella'. The umbrella,22 meters long and 11 meters wide, is made of five layers of material with extremely high reflectivity, each less than the diameter of human hair. This huge \"parasol\" will keep the telescope in the shade all the time, with temperatures no more than -223 degrees Celsius, and is suitable for observations in the target infrared band.

  总而言之,詹姆斯·韦伯望远镜的体积十分庞大,用一枚火箭都装不下。除了那把巨大的遮阳伞外,它的主镜直径达米,远超目前投入使用的任何火箭直径。既然不能把镜面“粘”在火箭一侧,聪明的NASA工程师们决定将镜面分成18片较小的六边形,这样就可以和折叠起来的“遮阳伞”、以及望远镜的其余部分一起塞进火箭里面了。

All in all, the James Webb telescope is so bulky that it won't fit with a single rocket. In addition to the giant umbrella, its main mirror has a diameter of dami, far more than any rocket currently in use. Since the mirror cannot be \"glued\" to the rocket's side, smart NASA engineers have decided to split it into 18 smaller hexagons so it can be stuffed into the rocket with folded umbrellas and the rest of the telescope.

  假如一切顺利,詹姆斯·韦伯望远镜发射升空几天后,就会朝观测点飞去,将镜面和遮阳伞展开到位,然后开始执行观测任务。

If all goes well, a few days after the launch of the James Webb telescope, it will fly towards the observation point, spread the mirror and the umbrella in place, and then begin the observation mission.

  而它的观测结果将极为惊人。该望远镜的主要观测目标之一将是早期宇宙,即宇宙刚刚诞生几亿年的时候。第一批出现的恒星和行星一度在可见光波段上发出耀眼的光芒。但在过去130亿年间,宇宙逐渐扩张,导致这些光线的波长越拉越长,最后离开了可见光、落入了红外光波段,正好属于詹姆斯·韦伯望远镜的理想观测范围。

And its observations will be stunning. One of the telescope's main observational targets will be the early universe, just a few hundred million years after its birth. The first stars and planets once shone brightly in the visible-light band. But over the past 13 billion years, the universe has gradually expanded, causing the wavelengths of these rays to pull longer, eventually leaving visible light and falling into the infrared light band, just within the ideal range of observations for the James Webb Telescope.

  詹姆斯·韦伯望远镜将对宇宙中一切“冰冷”的物体展开研究,包括围绕初生恒星的原行星盘、分子云、彗星、柯伊伯带等等。

The James Webb Telescope will look at all the \"icy\" objects in the universe, including the protoplanetary disk surrounding the primary star, the molecular cloud, the comet, the Kuiper belt and so on.

  该望远镜还将用一种特殊装置阻挡来自部分遥远恒星的光线,从而抓拍到任何从这些恒星前方经过的天体,如系外行星等。这些行星在红外波段内显得十分明亮,通过它们发出的光线,我们可以对行星大气中的化学物质和元素展开分析,说不定能从中发现生命的迹象。

The telescope will also use a special device to block light from some distant stars, capturing any celestial bodies, such as exoplanets, that pass in front of those stars. The planets are so bright in the infrared that through the light they emit, we can analyse the chemicals and elements in the planet's atmosphere, perhaps to find signs of life.

  总之,从搜寻外星生命、到揭开宇宙黎明时期的真相,詹姆斯·韦伯望远镜一定不会辜负我们多年的等待。(叶子)

In short, from searching for extraterrestrial life to uncovering the truth of the dawn of the universe, the James Webb Telescope will surely live up to our years of waiting. (Leaves)


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