David Bowie famously asked if there is life on Mars – to which humankind has repeatedly tried to supply an answer. But is there life on Titan? Paulette Clancy thinks it’s a question worth asking.
Clancy, professor in and head of the Department of Chemical and Biomolecular Engineering, is leading a team that recently received a Space@Hopkins research grant aimed at finding out. Entitled “Sheltering Life on Titan and Enceladus,” the project is focused on studying a molecule that may exist in the atmosphere of Saturn’s largest and sixth-largest moon, respectively.
“It’s called acrylonitrile … a short-chained molecule with a nitrogen atom at its head that self-assembles in what you might think of as an extraterrestrial membrane,” said Clancy, who is collaborating on the project with Shannon MacKenzie, planetary scientist and physicist at the Applied Physics Laboratory.
According to Clancy, the moons’ icy and beyond-freezing temperatures (-180C on Titan) would provide no advantage for a long-chained molecule, and the flexibility of membranes forming this particular molecule, known as an azotosome, appears similar to those observed on Earth.
“We posited that might be a requirement for life,” Clancy said.
The assumed structure for an azotosome has the molecules “lined up like soldiers,” Clancy said. Molecular simulation and ab initio models (based on established laws of nature) led the team to theorize that the Titan azotosome is fundamentally different. “Our preliminary results suggests that it forms a zig-zag structure,” Clancy said. “This may tip the stability for membranes over bulk crystals. We haven’t conclusively proved the membrane is more stable, but it’s probably competitive and that keeps the argument going.”
Clancy began work on this research, what she describes as a “cool little side project,” in 2015 while at Cornell University and said she has returned to it intermittently through the years. Clancy’s main projects focus on studying atomic- and molecular-scale modeling of semiconductor materials.
NASA detected the presence of acrylonitrile on Titan in 2017.
Three other teams were awarded Space@Hopkins grants, which encourage inter-departmental collaboration. Undergraduates are directly involved in the research as part of the grant stipulations.