There's a common misconception that Thor's hammer was forged from a dying star. It wasn't! It was forged inside of one, ya dummy. But just for fun, what would happen if Thor's hammer actually had been forged from a neutron star's demise?
Well, thanks to the newest Vsauce video, we have our answer: Nothing good. Just a sugar cube-sized bit of dying neutron star would have the same mass as roughly all of humanity—or 400 million metric tons. Now combine a bunch of those chunks into a hammer sized to fit the hand of a Norse god, and you're looking at 4.6 trillion metric tons. Or as the video puts it, "97 million Titanics condensed into the size of an American football." In other words, you have a pretty damn heavy hammer.