What’s new

China is nearing completion of the Jiangmen Underground Neutrino Observatory (JUNO), a $300 million facility designed to detect the most volatile particles in the universe – neutrinos.

Why it matters

Neutrinos are abundant, poorly understood subatomic particles dating back to the Big Bang. They are often nicknamed “ghost particles” because trillions of them pass through our bodies every second, containing almost no matter.

JUNO is one of three major neutrino detectors in development worldwide – the other two are under construction in the US and Japan.

What to know

Located 2,297 feet underground in Kaiping, Guangdong Province, JUNO has a 35.4-meter-diameter acrylic sphere filled with 20,000 tons of liquid scintillator.

This liquid will produce flashes of light when neutrinos collide with matter, which are detected by an array of 43,200 photomultipliers. Understanding neutrinos could provide critical insights into the origin and evolution of the universe, including why matter outnumbers antimatter.

The researchers say the project will be launched next year.

“The solution to how we measure these neutrinos is to build very, very large detectors,” said Andre de Gouvea, a theoretical physicist at Northwestern University who is not involved in the project.

“If they can do it, that would be amazing.”

The detector will focus on antineutrinos generated by nuclear reactors at a distance of more than 31 miles. When these particles interact with JUNO’s materials, they create measurable signals that scientists can analyze.

Despite being underground to avoid interference from cosmic rays and radiation, the sensitivity of the detector is unprecedented.

By comparison, Japan’s Hyper-Kamiokande is scheduled to be operational in 2027, and the US’s Deep Underground Neutrino Experiment (DUNE) aims for 2031.

What people are saying

Wang Yifang, JUNO’s principal scientist and project manager, said: “By studying neutrinos, we can understand why the universe became what it is today and what the future of the universe will be.”

Patrick Huber, director of the Center for Neutrino Physics at Virginia Tech, said: He described the project as an “exciting” opportunity to delve into some of the most fundamental — but elusive — building blocks of the universe.

J. Pedro Ochoa-Ricoux, a physicist at the University of California, Irvine, said: Internationally, the construction of JUNO was noted in the context of global scientific cooperation and competition. “Despite any political differences, I believe that through our collaboration on this scientific endeavor, we are setting a positive example that can contribute, even in a small way, to bringing our countries closer together.”

What happens next

JUNO is scheduled to begin collecting data in August 2025 with an expected operational lifetime of at least 30 years.

Once JUNO begins collecting data, it will take years to analyze the results.

All three detectors will eventually be able to cross-validate the findings and provide a more comprehensive understanding of neutrino physics than the last 50 years of research.

This article includes reporting from The Associated Press