Scientists think they've found all the 'missing' iron in the universe

These days, scientists think they have a pretty good idea of what the universe is made of. By detecting the telltale signatures of various elements in celestial bodies like stars, asteroids, and other planets, scientists can estimate how abundant or rare each of the known elements is. Iron, however, has proven to be tricky to nail down. We know iron is abundant on Earth as well as in stars, where the intense heat allows it to exist in the form of gas. That suggests that the element should also e...