Sometimes seeing things in a different light helps us better understand them. And sometimes you have to use completely different subatomic particles to achieve that.
Science writer Corey S. Powell shared this spectacular map of Earth on Twitter last night and people are amazed by how cool it is. The map was produced by the National Geospatial-Intelligence Agency (NGA) to track the production of antineutrinos from radioactive processes in the Earth’s crust and sometimes above it.
Antineutrinos and their regular matter counterparts are extremely light particles that are produced in both nuclear fusion and nuclear fission. They hardly interact with matter. Every second about 65 billion neutrinos come from the Sun and pass through an area the size of your index fingernail.
A lot of radioactive material is present inside our planet and the map and accompanying research, published in Scientific Reports, focused on the antineutrino emission from the radioactive decay of uranium and thorium. By looking for these antineutrinos, researchers can trace the continental crust pretty well because it is much thicker than the ocean crust. They can even see features like the Himalayan plateau or the sunken continent of Zealandia.
"The open access availability of these antineutrino maps represents the next generation of cartography and gives important insights into the basic understanding about the interior of our planet,” lead author Shawn Usman, NGA R&D scientist, said in a statement.
The map doesn’t only show the distribution of natural sources. The full analysis also shows the presence of nuclear reactors scattered around the surface of the planet. Only 1 percent of the antineutrinos emitted by our planet happens in reactors, the remaining 99 has to do with the natural radioactive decay of elements.
The largest source of antineutrinos is actually potassium, but the neutrinos released are not energetic enough to be seen by current instruments. Future detectors may reach that ideal sensitivity and provide an even better understanding of the processes happening under our feet.
“Geo-neutrino measurements are essential in characterizing the Earth’s radiogenic power across geologic time and in improving our understanding of planetary formation processes in the early solar nebula,” Usman added. “Our vision at NGA is to ‘Know the Earth…Show the Way…Understand the World.’ This map enhances our fundamental understanding of the planet by mapping out Earth’s natural and anthropogenic radioactivity.”
The NGA plans to periodically release updates on these maps. Better models, more sophisticated detectors, and the decommissioning of nuclear reactors guarantees that they will always be a bit different.
[H/T: Corey S. Powell]