Graphite Haze Formation in sub-Neptune Atmospheres within the Graphite-stability Regime

新的太空和地面望远镜将很快观测到其他恒星周围的行星，并在它们的大气层中寻找生命的迹象。亚海王星类型的行星是观测目标之一。然而，石墨雾预计会在许多亚海王星中形成，并可能阻碍我们的观测。约翰·霍普金斯大学领导的一个研究小组将通过实验探索海王星下大气中石墨雾的形成。它们将约束哪种类型的海王星下大气可能产生石墨雾，帮助选择未来的观测目标。他们还将测量石墨的性质，这对解释未来的观察结果至关重要。该团队将负责K-12教育和公共宣传项目。该项目将为6名代表性不足的学生提供研究实习机会。该研究将对系外行星大气化学领域的知识状况产生重大影响，对当前和未来系外行星大气表征工作至关重要。该团队将使用专门设计用于研究一系列行星大气的最先进的实验室设施，研究石墨稳定状态下海王星大气中发生的化学过程。他们将确定反应条件、成分变化以及石墨对关键大气气体光谱特征可探测性的影响。该团队将执行的具体任务包括：(1)限制石墨形成的条件，并确定在这些条件下的过渡效率；(2)测量气相组成，确定石墨形成的合理化学过程；(3)测量所得石墨雾从可见光到中红外的光学特性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

New space and ground-based telescopes will soon observe planets around other stars and search for signs of life in their atmospheres. The sub-Neptune type of planets are among the observing targets. However, graphite haze is expected to form in many of these sub-Neptunes and can block our observations. A team led by Johns Hopkins University will experimentally explore graphite haze formation in sub-Neptune atmospheres. They will constrain what type of sub-Neptune atmospheres are likely to produce graphite hazes, helping choose future observation targets. They will also measure the graphite’s properties critical for interpreting future observations. The team will conduct K-12 education and public outreach programs. This program will provide research internships for six underrepresented students.This research will make a significant impact on the state of knowledge in the field of exoplanet atmospheric chemistry, and is critical to current and future exoplanet atmospheric characterization efforts. The team will investigate chemical processes occurring in sub-Neptune atmospheres within the graphite-stability regime using a state-of-art laboratory facility specifically designed to investigate a range of planetary atmospheres. They will determine the reaction conditions, compositional alternation, and graphite’s impacts on the detectability of key atmospheric gas spectral features. The specific tasks that the team will perform include: (1) constraining the conditions for the formation of graphite and determine the transition efficiency under those conditions; (2) measuring the gas phase compositions and identify plausible chemical processes for the formation of graphite; (3) Measuring optical properties of the resulted graphite hazes from visible to mid-infrared.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.