Cosmic neutrinos are fleet-of-foot messengers from the distant cosmos. They're very difficult to detect and can only be detected on the rare occasions when they interact with other matter.

A new paper in Nature Astronomy presents plans for China's new neutrino observatory. It's titled "A multi-cubic-kilometre neutrino telescope in the western Pacific Ocean," and the lead author is Ziping Ye, a Postdoctoral Fellow in the Particle and Nuclear Division at the Tsung-Dao Lee Institute at Shanghai Jiao Tong University, Shanghai, China.

"Neutrino" means "little neutral one," and unless you're a physicist, a primer on neutrinos is helpful.

Neutrinos—and there are three sub-types—were discovered in the early 20th century. They have no electrical charge and an infinitesimal mass. In fact, some physicists initially thought they were massless. Without a charge, they don't interact with the electromagnetic force. They only interact through gravity and the weak nuclear force.

Neutrinos pass right through the Earth. Most of them come from the sun, which bombards every square center of the Earth that's facing the sun, with 65 billion of them every second. They have other sources, too, including supernovae, nuclear reactors, and other things, including the Big Bang.