The compound is plentiful on Mars, and crewed missions to the red planet in the future could conceivably take advantage of Martian methane to fuel trips back to Earth, said Chang. Burning methane also creates less soot than kerosene, another liquid-fuel option, making cleanup after a mission easier, said Martin Ross, an atmospheric scientist at the Aerospace Corp., a non-profit in El Segundo, California.

“Methane is so simple. You can make it in the laboratory and you can make it in a factory, presumably with renewable electricity,” he said. “So with methane we could be moving to a regime where rocket fuels are sustainable.”