Unraveling the Mystery of Helium-3 Leakage from Earth's Core.

Geoscientists have developed a theory to explain how helium-3 leaks from Earth's core into the mantle. They used first-principle calculations to show that helium-3 could enter magnesium oxide at the core-mantle boundary, allowing its entry into the mantle. Over the lifetime of the planet, as helium-3 was exsolved, it could have slowly made its way to parts of the mantle, where it may have risen to the surface through volcanic activity.