Smelly, toxic gas on other planets may be perfect proof of alien life

What do fish bowels, swamps, and mounds of penguin dung all have in common? A noxious gas that may be the best evidence for extraterrestrial life. That’s according to researchers with MIT, which reports that smelly and flammable phosphine gas is produced by a type of life form that doesn’t require oxygen to live. These organisms, it turns out, are …