"How did we get here?" is a long-standing question in planetary science. Characterizing the pre-biotic atmospheric environment in which life may emerge is critical and increasingly urgent. Given the fact that the Earth provides the only ground truth of habitable worlds, most of the characterizations are based on the current Earth. However, life did not emerge on the modern Earth. It instead took place in a prebiotic environment, which includes a nitrogen-dominated, methane-abundant and oxygen-negligible...