当科学家能够探测宇宙以前很久,人类就想象宇宙间别的地方有可能存在其它生命形式。但是现在,在拥有现代技术的情况下,科学家们已能够从事被称为地外智力探索了。但是关于宇宙间某处是否存在一个相当于我们人类的,或者比我们人类更先进的文明世界的可能性仍然辩论得很激烈。自从一九七一年以来,美国根据一顷地外智力探索计划的战略进行了四次广泛的研究,去年美国全国科学院天文研究委员会提供了一篇研究报告。建议作为一项国家的优先任务,实行一项得到适当规模支持的地外智力探索天文计划,作为一个长期的而不是短期的科研项目。美国国家航空和航天局也已经 Long before scientists could detect the universe, mankind imagined that there might be other life forms elsewhere in the universe. But now, with modern technology, scientists have been able to engage in what is known as extrinsic intelligence. But the possibility of somewhere in the universe where there is a civilized world comparable to ours or more advanced than ours is still debated intensely. Since 1971, the United States has carried out four extensive studies based on the strategy of a half-dozen extraterritorial intelligence exploration programs. Last year, the Astronomical Research Committee of the National Academy of Sciences of the United States provided a research report. It is proposed as a national priority to implement an extraterritorial intelligence exploration astronomy program, supported by a suitable scale, as a long-term rather than a short-term research project. The U.S. National Aeronautics and Space Administration already has it