Scientists examine ghostly particles emanating from deep within the Earth

Using a huge detector beneath an Italian mountain, scientist are studying neutrinos that are generated in our planet's hot interior.

|
Courtesy: INFN - Gran Sasso National Laboratories
The researchers detected neutrinos in Earth's mantle using the Borexino detector buried under a mountain at the Gran Sasso National Laboratory in Italy.

Using giant vats of organic liquid buried under a mountain in Italy, scientists have shed new light on the origins of ghostly particles known as neutrinos generated by the Earth.

This research could yield insights into what radioactive elements lie deep inside the Earth and how they influence the churning of the Earth's innards, researchers added.

Neutrinos are subatomic particles generated by nuclear reactions and the radioactive decay of unstable atoms. They are vanishingly tiny — 500,000 times lighter than the electron.

Neutrinos possess no electric charge and only rarely interact with other particles, so they can slip through matter easily — a light-year's worth of lead, equal to about 5.8 trillion miles (9.5 trillion kilometers) would only stop about half of the neutrinos flying through it. Still, neutrinos do occasionally strike atoms. When that happens, they give off telltale flashes of light, which scientists have previously spotted to confirm the particles' existence.

The decay of radioactive elements within the Earth sends out streams of neutrinos that scientists can detect on the Earth's surface. These "geoneutrinos" can offer novel insights into the planet's interior. For instance, although much of the Earth's internal heat is left over from its violent creation, some of it also comes from the decay of radioactive elements. But no one is certain how much. Geoneutrinos can reveal what different radioactive isotopes are scattered throughout Earth's interior and how their heat influences geological activity such as the flow of rock and any resulting earthquakes and volcanoes. [5 Mysterious Particles That May Lurk Beneath Earth's Surface]

"Heat sources will produce movements of large amount[s] of material," said study co-author Aldo Ianni, an experimental particle physicist at Gran Sasso National Laboratory in Italy.

To detect geoneutrinos, Ianni and his colleagues employed the Borexino neutrino detector at the Gran Sasso National Laboratory. This instrument uses more than 2,200 sensors to spot the flashes of light that neutrinos give off in the exceedingly rare instances in which they interact with nearly 300 tons of a special organic liquid. All of this is housed at the center of a large sphere surrounded by 2,400 tons of pure water about 1 mile (1.5 kilometers) under the Apennine Mountains.

The researchers now report the most extensive set of data yet collected for geoneutrinos. After analyzing 2,056 days of Borexino measurements, they detected about 24 geoneutrinos. They detailed their findings online Aug. 7 in the journal Physical Review D.

Analysis of the energies of these geoneutrinos suggests about 11 came from the Earth's mantle (the hot, rocky layer sandwiched between the core and crust) and about 13 came from the crust, Ianni said. The geoneutrinos the scientists have detected so far suggest that about 70 percent of the heat in the Earth's interior is due to radioactivity, although there is a great deal of uncertainty in that number, Ianni told Live Science. In order to get more definitive results, they would need to gather data for nearly another 17 years, he said.

Ianni said that in the future, scientists could place multiple geoneutrino detectors around the Earth. This could help researchers detect where radioactive elements spread throughout the Earth's interior, to help pinpoint how their heat influences the Earth's internal activity.

Follow Live Science@livescienceFacebook & Google+. Original article on Live Science.

Copyright 2015 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Scientists examine ghostly particles emanating from deep within the Earth
Read this article in
https://www.csmonitor.com/Science/2015/0820/Scientists-examine-ghostly-particles-emanating-from-deep-within-the-Earth
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe