On p. 10 of the 2018 National Academies Exoplanet Science Strategy document (NASEM 2018), ‘Expect the unexpected’ is described as a general principle of the exoplanet field. But for the next 150 pages, this principle is apparently forgotten, as strategy decisions are repeatedly put forward based on our expectations. This paper explores what exactly it might mean to ‘expect the unexpected’, and how this could possibly be achieved by the space science community. An analogy with financial investment strategies is considered, where a balanced portfolio of low/medium/high-risk investments is recommended. Whilst this kind of strategy would certainly be advisable in many scientific contexts (past and present), in certain contexts – especially exploratory science – a significant disanalogy needs to be factored in: financial investors cannot choose low-risk high-reward investments, but sometimes scientists can. The existence of low-risk high-impact projects in cutting-edge space science significantly reduces the warrant for investing in high-risk projects, at least in the short term. However, high-risk proposals need to be fairly judged alongside medium- and low-risk proposals, factoring in both the degree of possible reward and the expected cost of the project. Attitudes towards high-risk high-impact projects within NASA since 2009 are critically analysed.

中文翻译：

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在寻找外星生命的过程中期待意外

在页。2018 年美国国家科学院系外行星科学战略文件 (NASEM 2018) 的第 10 条，“期待意外”被描述为系外行星领域的一般原则。但在接下来的 150 页中，这一原则显然被遗忘了，因为战略决策是根据我们的预期反复提出的。本文探讨了“期待意外”的确切含义，以及空间科学界如何实现这一目标。考虑与金融投资策略进行类比，建议采用低/中/高风险投资的平衡组合。虽然这种策略在许多科学背景下（过去和现在）肯定是可取的，但在某些背景下——尤其是探索性科学——需要考虑一个重要的反类比：金融投资者不能选择低风险高回报的投资，但有时科学家可以。尖端空间科学中低风险高影响项目的存在显着降低了投资高风险项目的理由，至少在短期内如此。然而，高风险提案需要与中低风险提案一起公平判断，同时考虑可能的回报程度和项目的预期成本。自 2009 年以来，NASA 对高风险、高影响项目的态度得到了严格分析。高风险提案需要与中低风险提案一起公平判断，同时考虑可能的回报程度和项目的预期成本。自 2009 年以来，NASA 对高风险、高影响项目的态度得到了严格分析。高风险提案需要与中低风险提案一起公平判断，同时考虑可能的回报程度和项目的预期成本。自 2009 年以来，NASA 对高风险、高影响项目的态度得到了严格分析。