Building a framework for robust biosignature identification on rocky exoplanets

建立一个在岩石系外行星上进行稳健生物特征识别的框架

• 批准号: RGPIN-2022-04588
• 负责人: Rugheimer, Sarah
• 金额: $ 1.82万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=763081
• 关键词: Building; framework; robust; biosignature; identification

For the first time in human history, we are reaching the technological capability to detect biosignatures in the atmosphere of an exoplanet. This question of whether biology is unique to Earth lies at the intersection of astronomy, biology, geology and chemistry. My research program will drive forward understanding in three key areas to aid the remote detection of biosignatures on an exoplanet: 1) the impact of of a stars high energy radiation and activity, 2) how clouds affect observations and habitability, and 3) exploring false positive biosignature generation and disambiguation. All these areas centre around one overarching theme: how can we robustly distinguish life from non-life, light years away? One key target of my research program is to better understand the star-planet connection. The most exciting habitable exoplanet targets orbit flare stars, such as our nearest star, Proxima Centauri. However, we do not understand how flares impact atmospheres and our observations. Furthermore, for transiting habitable planets, the James Webb Space Telescope launching in December 2021 will need to add years of observations of separate transits to build up the signal required to detect atmospheric features, and we are unsure if there is variability in atmospheric features on those timescales. My research program will address this. A second area my group will work on is the impact of clouds on exoplanet atmosphere characterisation. Clouds are known to confound current exoplanet observations. Using 1D and 3D modelling tools, my group will learn more about clouds in different atmospheres and under different stellar radiation environments to better understand future exoplanet observations. The third area my program will explore is how to vet future biosignature claims. How robust a biosignature detection is requires an understanding of potential false positive mechanisms. There are several known false positive mechanisms for oxygen, the iconic biosignature, but we still don't know how atmospheric escape maybe linked with photochemistry. Nor has the influence of atmospheric pressure been looked at regarding a double gas biosignature false positive, particularly around flaring or UV active stars. My group will help establish ways for distinguishing known false positives from true biosignature detections. My research program is novel for two reasons - one is that we will tackle questions especially relevant for interpreting the first terrestrial exoplanet observations with JWST and address potential degenerate solutions. This work is designed to answer fundamental questions to understanding future biosignature detections and to capitalize on opportunities arising from JWST and other future missions. Two, my research program is also highly multidisciplinary. It links stellar astrophysics, exoplanet atmospheric modelling, climate, and geobiology. And hopefully, it will bring us closer to answering the age old question of "Are we alone in the Universe?"

在人类历史上，我们第一次达到了在系外行星大气中检测生物签名的技术能力。这个生物学是否是地球独有的问题在于天文学，生物学，地质和化学的交集。我的研究计划将推动在三个关键领域的理解前进，以帮助远程检测系外行星上的生物签名：1）恒星高能量辐射和活动的影响，2）云如何影响观察和可居住性，以及3）探索虚假积极的生物签名产生和歧义。所有这些领域以一个总体主题为中心：我们如何才能将生命与非生命，光明岁月相距甚远？我的研究计划的一个关键目标是更好地了解星空星际连接。最令人兴奋的宜居系外行星靶向轨道耀斑星，例如我们最近的恒星Proxima Centauri。但是，我们不了解耀斑如何影响气氛和我们的观察。此外，要为了传播可居住的行星，詹姆斯·韦伯（James Webb）太空望远镜于2021年12月推出将需要增加多年的单独过境的观察以建立检测大气特征所需的信号，我们不确定大气特征在这些特征上是否存在差异。时间尺度。我的研究计划将解决这个问题。 我小组将处理的第二个区域是云对系外星氛围的影响。已知云会混淆当前系外行星观测。使用1D和3D建模工具，我的小组将在不同气氛和不同恒星辐射环境中了解更多有关云的信息，以更好地了解未来的系外行星观测。我的计划将探索的第三个领域是如何审查未来的生物签名主张。生物签名检测的健壮程度需要了解潜在的假阳性机制。有几种已知的假阳性机制，即标志性的生物签名，但我们仍然不知道大气逃脱可能与光化学有联系。关于双气体生物签名假阳性，特别是在燃烧或紫外线活性星周围，也没有看到大气压力的影响。我的小组将帮助建立将已知误报与真实生物签名检测区分开的方法。我的研究计划是新颖的，有两个原因 - 一个是，我们将解决与JWST解释第一个陆地系外行星观测以及解决潜在退化解决方案有关的问题。这项工作旨在回答基本问题，以理解未来的生物签名检测，并利用JWST和其他未来任务引起的机会。第二，我的研究计划也是高度多学科的。它连接了恒星天体物理学，系外星大气建模，气候和地球生物学。希望这将使我们更加接近回答“我们一个人在宇宙中吗？”这个古老的问题。