Elon Musk shows off massive Starship, the world's tallest rocket, ahead of SpaceX up

Dec 3, 2019
SpaceX Starship is designed to start humans building a city on Mars but I have a bit of a question that is puzzling me. The air that we breathe is 80% nitrogen, are there significant quantities on Mars in the form of nitrates that the gas can be extracted from to replicate our atmosphere? Does anyone know?