Astrobiology suggest that life is abundant in the 宇宙 and the primitive microbial life forms (beyond earth) could be found earlier than intelligent forms. The search for the extra-terrestrial life involves looking for biological signatures in the vicinity of solar system and looking for radio signals or technical signatures in far away deeper space. There is case for renewed emphasis on searching technosignatures of life in the 宇宙.
如果这个星球之外还有生命？ 这个问题一直引起人们的兴趣，引起了很多轰动性和媒体的关注。 外星人 life forms. But where does science stands? Now we have a full-fledged interdisciplinary area of astrobiology dedicated to the study of the origin, evolution, and distribution of life in the 宇宙.
对问题 如果地球之外有生命, there is optimism about the possibility of extraterrestrial life (Billings L., 2018). NASA Kepler telescope has shown that the habitable worlds are abundant in the 宇宙. So are building blocks of life hence it seems reasonable to deduce that the life should be abundant in the 宇宙.
Is it really possible to find extra-terrestrial intelligence? Yes, there is increasing possibility due to technological advancements (Hirabayashi H. 2019). Therefore there certainly is a case for search of life on other planets; the extra-terrestrial life form could be primitive or complex and intelligent. Estimates suggests that there is relative likelihood of success in the searches for primitive life form than intelligent one (Lingam and Loeb, 2019). The dominant thinking in 天体生物学 is that the “first contact” with extra-terrestrial life may be with microbial life elsewhere (Billings L., 2018).
How do we search them? The search for 生活 ，在 宇宙 currently involves two approaches – search for biosignatures (签名 of biology) in and around solar system and radio search for technosignatures (signatures of advanced life forms and technology) emitted from sources far away from solar system in the galaxy and beyond. Projects like Mars and Europa landers, 詹姆斯韦伯太空望远镜 are aimed at search for signatures of biology in nearby solar system while NASA’s SETI (Search for Extra Terrestrial Intelligence) program and the Breakthrough Listen (BL) project are examples of search for technical signatures in far deeper space.
Both approaches offer benefits but the search for technosignatures seems to complement search for biology but also expands search from solar neighbourhood to deeper in 宇宙 into galaxies.
搜索涉及定向、记录和分析无线电信号或来自深空的爆发的技术签名的成本相对较低（与搜索生物签名相比）。 例如，NASA 的 SETI 计划的年度预算约为 10 万美元。 大部分空间都可以定位和搜索具有强大信息内容、强大检测和解释能力的无线电信号。 此外，无线电搜索具有既定的科学背景和背景。
搜索技术签名也是因为到目前为止采样的搜索量非常低。 搜索量可能会在不久的将来扩大。 这将需要加强对射电望远镜、资源的访问，重建研究生态系统并跟上硬件和软件的进步（Margot 等人，2019 年）。
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编者注：
加州大学洛杉矶分校的 Jean-Luc Margot 博士建议 'NASA 没有 SETI 计划。 它已经超过 25 年没有 SETI 计划了。 请考虑更正。'。
我们想补充一点，NASA 的 SETI 计划在 1993 年被取消。当时 SETI 计划的年度预算约为 10 万美元。
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来源（S）
1. Margot J 等人 2019. 2020-2030 十年间对技术签名的无线电搜索。 预印本 arXiv:1903.05544 于（13 年 2019 月 XNUMX 日）提交。 https://arxiv.org/abs/1903.05544
2. Billings L.，2018 年。从地球到宇宙：生命、智能和进化。 生物理论。 13（2）。 https://doi.org/10.1007/s13752-017-0266-6
3. Hirabayashi H. 2019. SETI（搜寻地外文明）。 天体生物学。 https://doi.org/10.1007/978-981-13-3639-3_30
4. Lingam M 和 Loeb A 2019. 寻找原始与智能外星生命的相对成功率。 天体生物学。 19（1）。 https://doi.org/10.1089/ast.2018.1936
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