A Mysterious Cosmic Signal Has Baffled Scientists — and One Clue Could Explain It

A strange signal detected by LIGO has opened one of the most intriguing questions in modern cosmology: did scientists just hear evidence of a black hole that was not born from a dying star? The clue lies in its possible mass, because at least one object in the detected merger may have weighed less than the Sun.

That detail matters because ordinary stellar black holes usually form after massive stars collapse, making subsolar black holes difficult to explain through standard astrophysics. University of Miami researchers Nico Cappelluti and Alberto Magaraggia argue that the signal could point to a primordial black hole, a theoretical object formed in the first moments after the Big Bang.