Each second, more than 10 septillion (1025) antineutrinos race away from Earth and into space. That’s 100 trillion times as many antineutrinos as stars in the galaxy. But who’s counting?
Leave that to particle physicist Shawn Usman of the National Geospatial-Intelligence Agency in Springfield, Va. In September in Scientific Reports, he and colleagues published the first global map of antineutrinos, harmless subatomic particles (and the antimatter cousins of neutrinos) born when radioactive elements break down. That decay happens within the planet’s crust and mantle and in nuclear reactors.
Usman’s team pieced together data, including measurements from detectors in Italy and Japan, to build a Technicolor map of antineutrino abundance. Dark reds flag hot spots; blues mark areas where antineutrinos are less bountiful.
The map could help scientists nail down the driver of Earth’s internal heating system, which fuels plate tectonics and volcanoes. Just how much heat comes from radioactive energy in the planet is still up for debate, Usman says. His team’s map might offer researchers a clearer picture. And it will certainly be more colorful.