Background
Uranus is an important destination for the planetary science community. The recent Decadal Survey recommended that NASA initiate a flagship mission to Uranus within the next decade. We expect that there will be opportunities in the next few years to propose to join the mission’s science team and develop instruments for the mission. The overarching aim of this project was to advance our expertise in topics that are central to Uranian system science.
Approach
We performed literature research to identify gaps in our current understanding of Uranus and its moons. We determined that the community is not prepared to interpret future mass spectrometry data on the bulk elemental composition of Uranus’s atmosphere. This is because the interpretation rests on knowing the protosolar abundances of volatile elements, which have too much uncertainty. We decided to tackle the solar abundances problem. We performed extensive research on the solar composition and relevant cosmochemical sources of information. Many of the data we used are novel to the present application.
Accomplishments
We developed a new model of solar nebula chemistry. Most notably, we found that the solar C/O ratio is likely larger than the current, widely adopted value. The implication is that planetary building blocks should contain less water ice than implied by previous models. Our model is applicable across the outer solar system, as it was found to be consistent with data spanning from CI carbonaceous chondrites to comet 67P. In the future, we will use this model to predict the bulk elemental composition of Uranus’s atmosphere for different origin scenarios. A paper on the model was written and is in press at The Astrophysical Journal (Truong et al., 2024). Ngoc Truong also gave several talks on the model to the wider community.