John Metcalfe is CityLab’s Bay Area bureau chief, based in Oakland. His coverage focuses on climate change and the science of cities.
The tiniest particles known to science are rocketing out of the earth and our energy facilities.
Here’s a fun science fact: Your body is constantly being pummeled with tiny particles traveling nearly the speed of light. They’re called neutrinos and antineutrinos—the smallest-known subatomic particles—and they fly out of nuclear reactions taking place in the sun, black holes, and in the red-hot bowels of the earth.
Scientists at the National Geospatial-Intelligence Agency and elsewhere recently made history with what they call the first map of global antineutrino activity. Their glowing cartography shows areas of radioactive emissions in orange and (higher still) deep red.
While there are many cool aspects to the project, especially if you have a degree in physics, simple joy can be found in lining up the most intense antineutrino fountains with the planet’s nuclear reactors. Look for maroon pinpricks, especially in the Eastern U.S. and Europe, and compare their locations with this reactor map from Climate Central:
This new view of the planet will likely come in handy in a number of applications, nonproliferation efforts being a biggy. In a University of Maryland press release, the scientists explain how they created it and what their hopes are for the future:
Neutrinos are notoriously difficult to study; their tiny size and lack of electrical charge enables them to pass straight through matter without reacting. At any given moment, trillions of neutrinos are passing through every structure and living thing on Earth. Luckily, antineutrinos are slightly easier to detect, through a process known as inverse beta decay. Spotting these reactions requires a huge detector the size of a small office building, housed about a mile underground to shield it from cosmic rays that could yield false positive results.
In the current study, the team analyzed data collected from two such detectors—one in Italy and one in Japan—to generate a picture of antineutrino emissions from natural sources deep within Earth. They combined this with data collected by the International Atomic Energy Agency (IAEA) on more than 400 operational nuclear reactors. In total, antineutrinos from these human-made sources accounted for less than 1 percent of the total detected.
"Keeping tabs on nuclear reactors is important for international safety and security. But as a geologist, I'm particularly excited for the potential to learn more about Earth's interior," McDonough said. "This project will allow us to access basic information about the planet's fuel budget across geologic time scales, and might yet reveal new and exciting details on the structure of the deep Earth."