The Earth sits 93 million miles from the sun, which means any plasma-based temper tantrums have to travel a serious distance before affecting us. But habitable planets have to orbit nice and close to red dwarf stars—you can’t get all that far away from them before it gets too cold for water to stay wet. This means that if you want to take a vacation to Proxima b, the not-fun-at-all name we give to the exoplanet orbiting our nearest neighbor—you’d best pack some sunscreen.
