Helium-3, a rare isotope formed during the early solar system, may be locked within Earth’s solid core, as indicated by recent research. This discovery could provide insights into how quickly the planet was formed. Unlike helium-4, which is commonly produced through radioactive decay, helium-3 originates from the primordial gas cloud that shaped the solar system. While traces of this isotope have been detected in volcanic hotspots and mid-ocean ridges, the mechanism behind its retention for billions of years remains uncertain. Given helium’s volatile nature, most of it was expected to escape Earth’s mantle due to tectonic activity or the giant impact that led to the formation of the Moon. Helium and Iron Interaction at Core Conditions According to the study published in Physical Review Letters, researchers at the University of Tokyo led by Kei Hirose examined whether helium could mix with iron under conditions mimicking Earth’s core. Using a diamond-tipped anvil, the team subjected iron and helium to extreme pressures ranging from 50,000 to 550,000 times the atmospheric pressure at Earth’s surface. As per reports, …