It's a God-awful smell affair.... is there life on Mars? Rocks ruled out as source of mystery methane on Red Planet

(Yes, pedants, we know natural methane is odorless. Don't get in the way of a Bowie headline)

Ever since methane was detected on Mars, boffins have been trying to find out how it got there. Research published in Scientific Reports on Monday has ruled out one source - rocks being eroded by wind."