[…]to accurately interpret some of the neutron stars’ signals, researchers must first understand what goes on inside them. They have their hunches, but experimenting directly on a neutron star is out of the question. So scientists need another way to test their theories. The behavior of matter in such a superdense object is so complicated that even computer simulations aren’t up to the task. But researchers think they may have found a solution: an earthly analog.

Though young neutron stars can have temperatures in the millions of degrees in their interior, by one important energetic measure neutrons are considered “cold.” Physicists think that is a characteristic they can exploit to study the inner workings of neutron stars. Instead of looking to the sky, researchers are peering into clouds of ultracold atoms created in laboratories here on Earth. And that might help them finally answer some longs