Extraterrestrial chemistry with earthbound possibilities | Science & Technology

Undergraduate student Kennedy Barnes will present the team’s results at the fall meeting of the American Chemical Society (ACS).

“The first detection of molecules in space was made by Wellesley College alum Annie Jump Cannon more than a hundred years ago,” says Barnes, who, with fellow undergraduate Rong Wu, led this study at Wellesley, mentored by chemistry professor Christopher Arumainayagam and physics professor James Battat. Since Cannon’s discovery, scientists have been interested in finding out how extraterrestrial molecules form. “Our goal is to explore the relative importance of low-energy electrons versus photons in instigating the chemical reactions responsible for the extraterrestrial synthesis of these prebiotic molecules,” Barnes explains.

The few studies that previously probed this question suggested that both electrons and photons can catalyze the same reactions. Studies by Barnes and colleagues, however, hint that the prebiotic molecule yield from low-energy electrons and photons could be significantly different in space. “Our calculations suggest that the number of cosmic-ray-induced electrons within cosmic ice could be much greater than the number of photons striking the ice,” Barnes explains. “Therefore, electrons likely play a more significant role than photons in the extraterrestrial synthesis of prebiotic molecules.”

Aside from cosmic ice, her research into low-energy electrons and radiation chemistry also has potential…