Project 10

This project is in the area of astrobiology which spans fields including astronomy, biology, ecology, among others. We have developed a novel method for
estimating possible biological evolutionary stage on exoplanets based on the hypothesis that biological evolutionary state is a linear function of
cumulative carbon fixed (photosynthesis) on an entire planet. We have demonstrated the implications of this hypothesis using spatially explicit climate
simulations of TRAPPIST-1e, a tidally locked planet within the habitable zone of a red dwarf star ~40 light years away. We estimate that Earth has
cumulatively fixed ~9.4x 10^25 g C carbon, and TRAPPIST 1e (T1e) as an ocean world with 400 ppm CO2 using photon energy of wavelengths 400-
1100 nm would need 2218 Gy years to fix the same amount of carbon. Since T1e’s mean estimated age is 7.6 Gyr, we estimate it to be at a potential
microbial, but not multicellular life stage. We applied the same technique to 29 nearby exoplanets that may have the conditions suitable for harboring life
and using 400-1100nm light and identify two planets that surpass Earth’s cumulative NPP and which could have both multicellular and intelligent life and 56 planets at the potential multicellular stage. The model and results described above rely on very basic assumptions regarding atmospheric and
ecological processes. The goal of this project is to improve the model assumptions by incorporating additional atmospheric and ecological constraints
into the model.

The work will require reading papers from the literature, programming a computer, meeting weekly with co-advisors Doughty and Gowanlock, and virtual meetings with our collaborators at other institutions. The project will require roughly 10 hours/week of work.

The work we envision is fairly straightforward and we hope that it will (ideally) yield a student-led publication. We expect that the student will have to
present informally at our meetings with our collaborators in addition to at least one formal presentation. Additionally, the source code of the model will be another another research artifact that the student will develop.