Vaccinations, in one form or another, have been around longer than the United States. In fact, during the Revolutionary War in 1776, future first lady Abigail Adams pursued the controversial scientific technique to protect her 5 children against a threat more dangerous than an army of Redcoats....

Cosmic rays from outer space sound like science fiction. They’re not—invisible particles flung from outer space pass through our bodies every minute. But not all cosmic rays are equal; Some are immensely powerful and very rare. For decades scientists have wondered where they're coming from – and...