SETI 的历史 - 11

Youth讨论 | 贡献2010年8月1日 (日) 11:09的版本
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<资料来源:The Planetary Society>


While most SETI searches were modest, local affairs, this was not always the case. The most ambitious of all SETI searches was conducted by NASA, which had access to funding and resources on a completely different scale than any of the other searches. Indeed - NASA involvement in SETI was decisive, both in gaining mainstream respectability for the extraterrestrial search and in advancing the search technology to levels undreamt of by the Ozma pioneers. At the same time, the NASA search also demonstrated the risks of dependence on government funding: during times of budget cuts in Washington, the SETI project turned out to be extremely vulnerable to changing political winds.

虽然大部分 SETI 搜索活动都是比较低调的,但这并不是所有的情况。SETI 史上最高调的搜索活动是由 NASA 主导的,后者所能掌控的现金和资源在数量上都远超其它搜索项目。确实,NASA 对 SETI 搜索活动的介入是决定性的,一方面为地外文明搜索赢得了主流社会的尊重,另一方面也将搜索技术推进到了当初的 Ozma 项目所难以想像的层次。与此同时,NASA 的介入也证实了由政府来提供资金进行搜索活动所带来的风险,在预算被华盛顿削减的日子里,SETI 项目在飘乎不定的政治风向面前实际上是极度脆弱的。

Cyclops 项目报告
Cyclops 项目报告的封面。

In 1970 John Billingham of NASA's Ames Research Center in Mountain View, California, convinced Ames director Henry Mark to start a small study of SETI strategies and the likelihood of contacting an alien civilization. The result was "Project Cyclops," a 1971 summer faculty fellowship program sponsored by Stanford University and NASA Ames.

1970 年,位于加州山景区的 NASA Ames 研究中心,John Billingham 说服了 Ames 的主管 Henry Mark,来启动一个关于 SETI 搜索策略和与外星文明进行联系的小型研究课题。然后“Cyclops(译注:希腊神话里的独眼巨人)计划”就在 1971 年夏天就诞生了,一个由由斯坦福大学和 NASA 资助的机构合作项目。

The moving spirit behind the study was Bernard M. Oliver, the Hewlett Packard VP who we've already met at the 1961 Green Bank conference. The proposal that emerged from the study, under Bernard's leadership, was ambitious indeed. It envisioned a forest of about one thousand 100-meter (about 300 ft) dishes, occupying an area of about 10 kilometers in diameter. If we remember that ten years earlier project Ozma was conducted with a single 85 ft telescope, we might get an idea of the scale of the project Oliver and his colleagues were proposing. Ozma cost $2000; Cyclops called for an investment of $10 billion!

该课题背后的策划者是我们在 1961 年 Green Bank 会议上已经见过的 Bernard M. Oliver,HP 公司的副总裁。在 Bernard 的领导下,从这个课题中产生了一项非常有雄心的提案。它设想了一个由 100 个 100 米直径的碟状天线组成的阵列,占地面积十公里见方。如果我们还对 10 年前 Ozma 项目中所使用的 85 英尺望远镜有印象,那我们对 Oliver 和他的同事们所做出的这个提案的规模会有更直观的感受。Ozma 项目花费了 2000 美元,而 Cyclops 项目打算要求 100 亿美元!

The scale of the project was well beyond anything NASA would or could sanction. Its primary mission was launching spacecraft, and a SETI search would always be a sideshow for NASA. But even a small NASA program could command resources far in excess of anything available for SETI previously.

该项计划完全超出了 NASA 愿意承受和能够承受的范围。NASA 的主要任务应该是发射太空飞船,SETI 搜索只可能是 NASA 的附属任务。但即便是 NASA 的一个小项目都能够支配的资源都远超出之前其它任何 SETI 项目。

Bruce Murray
JPL(喷气推进实验室)的前任主管和行星协会(The Planetary Society)的创建人

Over the next ten years, NASA continued to sponsor workshops and studies on the feasibility of SETI. Gradually, two main search strategies emerged. One approach, sponsored by NASA Ames, favored the traditional, "targeted" search. As with most (though not all) previous searches, the idea was to select certain stars, which were similar to our sun and relatively nearby, and listen carefully to any signals emanating from them. These stars, the argument went, offered the best chance of establishing contact with an alien civilization.

之后的十年,NASA 仍在继续对 SETI 可行性相关的研讨会和研究项目进行资助。逐渐的,两种主要的搜索策略浮现水面。第一种,由 NASA Ames 资助,是传统的、有针对性的搜索。就和之前大部分(不是所有的)搜索项目一样,这种策略是选择特定的恒星,也就是那些和我们的太阳比较相似,而且距离不太远的,然后仔细监听上面发出的任何信号。该策略认为这些恒星对于与外星文明进行接触提供了最好的机会。

The other approach advocated a "full sky survey," and it was championed by Bruce Murray, director of the Jet Propulsion laboratory (JPL) in Pasadena. According to Murray it was futile to speculate where alien civilizations would be found. It was also useless to make any assumptions as to what frequency they would be transmitting in. The fact is, Murray insisted, that we just don't know. The only reasonable route is to systematically search the entire sky for a signal on the widest band of frequencies possible. Such a search would not be as sensitive as a targeted search, but it would make up for that by its breadth and scope.

另一种策略则提倡“全天搜索”,这种策略为位于 Pasadena 的 JPL(喷气推进实验室)主管 Bruce Murray 所推崇。他认为假定能在哪里找到外星文明是不靠谱的,而假定能在哪些频率收到外星文明发来的信号也是不靠谱的,所有这些,Murray 坚持认为,我们并不清楚。而唯一可行的方法就是在所有可能的频率带宽上进行系统的全天搜索。这样的搜索可能没有针对性搜索那样灵敏,但这可以通过搜索的广度和深度来进行补偿。

By 1979 NASA had in place the outlines of a coherent SETI plan. Instead of choosing between the competing approaches, NASA decided to pursue them both. A targeted search would be based at NASA Ames, while an all-sky survey would be headquartered at JPL. An official NASA project named the "Microwave Observing Program" (MOP) was established to conduct the search, following a period of research and development.

到 1979 年,NASA 的 SETI 计划已经初具雏形。不是在相互竞争的方案中选择某一个,NASA 决定两个方案同时进行。有针对性的搜索由 NASA Ames 来执行,而全天搜索由 JPL 来领导。在经过一段时期的研发准备后,NASA 的官方 SETI 搜索项目正式成立,名为“微波观测计划(Microwave Observing Program,简称 MOP)”。

月基 SETI(Lunar SETI)
一位作家的构思:在月球背面建立 Cyclops SETI 望远镜阵列。
An artist's rendition of a Cyclops SETI telescope array on the dark side of the moon.

第10章:“哇!” ← | → 第12章:SETI 到华盛顿