For years, fast radio bursts have mystified astronomers across the planet. These millisecond-long blips of intense, unexplained radio signals pop up all over the sky, temporarily outshining radio pulsars despite being perhaps a million times farther away. Before 2013, many astrophysicists doubted that they even existed. Now their existence is undeniable — but what exactly are they? Learn more about your ad-choices at https://news.iheart.com/podcast-advertisers