A robot just made oxygen on Mars, which is a huge deal

Robots are a lot easier to send to other planets than humans are. For one, they don't complain nearly as much. On top of that, they don't need pesky things like food or breathable air. Of course, if we're ever going to send humans to Mars -- as space agencies around the globe have pledged to do within the next few decades -- we're going to have to figure out a way to either send those things along for the trip or make them once the missions arrive. NASA's Perseverance rover may have just taken a...