Among other things, the model tracked the formation of intermediate molecules that eventually turned into glycine, a simple amino acid that often shows up in Miller-type experiments. Before the gases made glycine, they first made organic chemicals including formic acid and formamide, the model found. In their paper in Proceedings of the National Academy of Sciences, the scientists suggest that astronomers could look for these molecules on other planets and solar systems. They could be signs of the kinds of reactions that led to life on Earth.