What are the little red dots? It's the question that has quietly obsessed astronomers since the James Webb Space Telescope first opened its eyes and started revealing the early universe in unprecedented detail. Hundreds of tiny, faint, reddish objects all sitting some 12 billion light years away, meaning we see them as they existed when the universe was barely a toddler. They showed up almost immediately and nobody could agree on what they were. Now, one maverick object hiding in a decade old data archive might finally have cracked it.

The leading theory for these so called little red dots is as exotic as it sounds.…