Scientists have tentatively identified several particles lurking deep inside the Earth's mantle that could reveal how much heat the planet produces and confirm that the Earth formed from materials from the sun.
The wacky particles are called geoneutrinos, or the antimatter partners of neutrinos (exotic fundamental particles that can pass right through Earth), that form deep within the Earth's mantle. Every matter particle has an antimatter partner particle that has an opposite charge, and when the two meet they annihilate each other. The findings were detailed described March 11 in the preprint journal arXiv.org.
Geoneutrinos aren't the only particles scientists are hoping to find inside Earth. An experiment using the Earth as a source of electrons recently narrowed down the search for a new force-bearing particle, possibly the so-called unparticle, placing tighter limits on the force it carries.
When Earth formed, the radioactive elements thorium and uranium were distributed in Earth's interior at different concentrations within the crust (the planet's outer layer) and mantle. As these elements within the mantle radioactively decay, they give off heat and also form subatomic particles known as geoneutrinos, said study co-author Aldo Ianni, a physicist at the Gran Sasso National Laboratory in Italy.