Seeding life on habitable planets

在宜居行星上播种生命

• 批准号: MR/T040726/1
• 负责人: Catherine Walsh
• 金额: $ 145.81万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FT040726%2F1
• 关键词: Seeding; life; habitable; planets

Two of the great quests of humankind are the hunt for habitable planets and the search for the signatures of life beyond planet Earth. To date, we have discovered more than 4000 planets orbiting other stars, the so-called exoplanets. Of these exoplanets, 21 have a similar size to Earth and also orbit their host star in the habitable zone, a temperate region where liquid water may be able to survive on the planet surface. However, a planet's presence within this temperate zone is only one of several criteria that determines whether or not a planet is truly habitable. So far, we know of only one place in the universe where life has begun and thrived, planet Earth. It is still not well understood why the Earth is seemingly the only planet in the Solar System where life has flourished, especially because our neighbour, Venus, also orbits within the temperate region around the Sun, yet has an atmosphere and surface that is not friendly for life. Rocky planets like the Earth and Venus are formed from cataclysmic collisions of moon-sized bodies, the energy from which would have created a molten, hot surface from which volatiles, such as water, would have boiled away to space.So what happened to make the Earth life friendly? One theory that has stood against scrutiny is that impacts from comets, icy leftovers from the formation of the Solar System, delivered a substantial volume of water and life-friendly (carbon-rich) ingredients to the surface of the young Earth when the crust cooled and solidified. This replenished the planet with the ingredients needed for life to begin. However, this then raises questions on the role of comets in seeding *all* potentially habitable planets with life-friendly ingredients. Are cometary impacts a vital process in the formation of a habitable planet? If so, are comets formed around other stars also carriers of carbon-rich and life-friendly material?This research will scrutinise the criteria needed for habitability by investigating the role of comets in seeding life on *all* potentially habitable planets, using state-of-the-art computational chemical and climate models, in conjunction with state-of-the-art observations of comets and exo-comet forming regions around other stars. My team and I will determine i) whether or not the comet-building material in exoplanet-forming systems are universal carriers of organic-rich material needed to seed life, and ii) whether or not cometary impacts on the atmospheres of rocky exoplanets are an observable phenomenon. The outputs from this research will provide strong constraints on the commonality of habitable planets, and provide a suite of diagnostics to search for evidence of cometary impacts using next generation telescopes that will target potentially habitable exoplanets. This research will revise the definition of "habitability" and will provide atmospheric diagnostics of habitability beyond the already proposed biosignatures.

人类的两个伟大追求是寻找可居住的行星，并寻找地球之外的生命签名。迄今为止，我们发现了4000多个绕着其他恒星的行星，即所谓的系外行星。在这些系外行星中，有21个具有与地球相似的大小，并且在宜居区绕着其宿主恒星绕，该区域是液态水可能能够在行星表面生存的温带区域。但是，行星在这个温带区域的存在只是确定行星是否真正可居住的几个标准之一。到目前为止，我们只知道宇宙中生命开始和蓬勃发展的一个地方，地球。仍然不太清楚为什么地球似乎是太阳系中生命蓬勃发展的唯一行星，尤其是因为我们的邻居维纳斯（Venus）也是太阳周围温带地区的轨道，但具有对生命不友好的气氛和表面。像地球和金星这样的岩石行星是由月亮大小的身体的灾难性碰撞形成的，这种能量会产生熔融，热的表面，挥发物（例如水）会沸腾到太空。那么发生了什么使地球生命友好的事情？反对审查的一种理论是，彗星的影响，太阳系形成的冰冷剩菜，在外壳冷却和固体时，将大量的水和生命友好（富含碳富含碳的）成分传递到了年轻地球的表面。这为地球补充了生命所需的成分。但是，这就提出了有关彗星在种子中的作用 *所有 *所有 *可能可居住的行星，并具有生命友好的成分。彗星在形成宜居星球的形成中是否会影响至关重要的过程？如果是这样，其他恒星周围是否还形成了富含碳和生命友好的材料的载体？这项研究将通过调查彗星在 * All * All *潜在的可居住行星上的作用，使用最先进的计算化学和气候模型，与众所周知的星星相结合，来审查彗星在 * All * All *潜在可居住的行星上的作用，来审查可居住性所需的标准。我和我的团队将确定i）外部形成系统中的彗星建造材料是否是播种生命所需的有机富含有机材料的通用载体，ii）ii）彗星对岩石外球星的大气的影响是否是可观察到的现象。这项研究的产量将对可居住行星的共同点提供强大的限制，并提供一套诊断，以寻求使用下一代望远镜的彗星影响的证据，该望远镜将针对潜在的可居住系外行星。这项研究将修改“可居住性”的定义，并将为已经提出的生物签名外提供大气诊断。

项目成果

Molecules with ALMA at Planet-forming Scales (MAPS). XV. Tracing Protoplanetary Disk Structure within 20 au

• DOI: 10.3847/1538-4365/ac1433
• 发表时间: 2021-09
• 期刊: The Astrophysical Journal Supplement Series
• 作者: A. Bosman;E. Bergin;R. Loomis;S. Andrews;M. V. ’. van ’t Hoff;R. Teague;K. Öberg;V. Guzmán;C. Walsh;Y. Aikawa;Felipe Alarc'on;J. Bae;J. Bergner;A. Booth;G. Cataldi;L. Cleeves;I. Czekala;Jane Huang;J. Ilee;C. Law;R. Le Gal;Yao Liu;F. Long;F. Ménard;H. Nomura;L. Pérez;C. Qi;K. Schwarz;A. Sierra;T. Tsukagoshi;Yoshihide Yamato;D. Wilner;Kecheng Zhang

Molecules with ALMA at Planet-forming Scales (MAPS): A Circumplanetary Disk Candidate in Molecular-line Emission in the AS 209 Disk

• DOI: 10.3847/2041-8213/ac7fa3
• 发表时间: 2022-07
• 期刊: The Astrophysical Journal Letters
• 作者: J. Bae;R. Teague;S. Andrews;M. Benisty;S. Facchini;Maria Galloway-Sprietsma;R. Loomis;Y. Aikawa;Felipe Alarcón;E. Bergin;J. Bergner;A. Booth;G. Cataldi;L. Cleeves;I. Czekala;V. Guzmán;Jane Huang;J. Ilee;N. Kurtovic;C. Law;R. L. Gal;Yao Liu;F. Long;F. Ménard;K. Oberg;L. Pérez;C. Qi;K. Schwarz;A. Sierra;Catherine Walsh;D. Wilner;Kecheng Zhang

Molecules with ALMA at Planet-forming Scales (MAPS). VII. Substellar O/H and C/H and Superstellar C/O in Planet-feeding Gas

• DOI: 10.3847/1538-4365/ac1435
• 发表时间: 2021-09
• 期刊: The Astrophysical Journal Supplement Series
• 作者: A. Bosman;Felipe Alarc'on;E. Bergin;Kecheng Zhang;Merel L. R. van’t Hoff;K. Öberg;V. Guzmán;C. Walsh;Y. Aikawa;S. Andrews;J. Bergner;A. Booth;G. Cataldi;L. Cleeves;I. Czekala;K. Furuya;Jane Huang;J. Ilee;C. Law;R. Le Gal;Yao Liu;F. Long;R. Loomis;F. Ménard;H. Nomura;C. Qi;K. Schwarz;R. Teague;T. Tsukagoshi;Yoshihide Yamato;D. Wilner

Molecules with ALMA at Planet-forming Scales (MAPS). XVI. Characterizing the Impact of the Molecular Wind on the Evolution of the HD 163296 System

• DOI: 10.3847/1538-4365/ac1ad4
• 发表时间: 2021-09
• 期刊: The Astrophysical Journal Supplement Series
• 作者: A. Booth;B. Tabone;J. Ilee;C. Walsh;Y. Aikawa;S. Andrews;J. Bae;E. Bergin;J. Bergner;A. Bos

Molecules with ALMA at Planet-forming Scales (MAPS). XI. CN and HCN as Tracers of Photochemistry in Disks

• DOI: 10.3847/1538-4365/ac143a
• 发表时间: 2021-09
• 期刊: The Astrophysical Journal Supplement Series
• 作者: J. Bergner;K. Öberg;V. Guzmán;C. Law;R. Loomis;G. Cataldi;A. Bosman;Y. Aikawa;S. Andrews;E. Bergin;A. Booth;L. Cleeves;I. Czekala;Jane Huang;J. Ilee;R. Le Gal;F. Long;H. Nomura;F. Ménard;C. Qi;K. Schwarz;R. Teague;T. Tsukagoshi;C. Walsh;D. Wilner;Yoshihide Yamato