Researchers at the Gran Sasso National Laboratory in Italy have made some interesting findings: they’ve observed “ghost particles” called geoneutrinos that is revealing some rather astonishing facts about our planet.

A total of 24 geoneutrinos were recorded, also known colloquially as ghost particles, and it’s the first firm evidence that they’re coming not from the surrounding environment or the Earth’s crust, but deep within the Earth, according to a Daily Mail report.

It’s a very important finding that could help researchers understand the radioactive makeup of Earth, and how this radioactivity generates heat.

These so-called “ghost particles” are actually neutrinos, which are created from nuclear reactions when atoms that are unstable decay. They are very, very small — its mass is 500,000 times less than that of a singl electron. Because of this, they rarely interact with other particles, and only extremely seldomly strike atoms. They also don’t carry a charge.

It’s those rare moments when it does manage to collide into an atom that scientists were looking for. When it happens, there is a flash of light, which is the only direct evidence that they exist. Using the laboratory, which is deep underground, they were able to prove that some of them were coming from the Earth’s interior, providing a rare glimpse of what’s going on in our planet’s core.

Thanks to the new research, scientists will be able to pinpoint the individual radioactive isotopes and use that information to better understand how the heat they generate causes geological phenomena like volcanoes and earthquakes.

Much of the heat in the Earth’s interior is simply left over from its formation, but the remainder of it comes from the decay of radioactive elements. However, until now, scientists had no idea how much of it came from that process.

Using the lab, they were able to set up 2,200 sensors to spot these flashes using the Borexino neutrino detector. They created a sphere in the laboratory containing a special oil to help catch a glimpse of these neutrinos. A total of 24 were observed in 2,056 days, with 11 coming from the mantle of the Earth and 13 coming from the crust.