High-precision noble gas analyses indicate that solar wind particles from our primordial Sun were encased in the Earth's core over 4.5 billion years ago. Researchers from Heidelberg University have concluded that the particles made their way into the overlying rock mantle over millions of years. The scientists found solar noble gases in an iron meteorite they studied. Because of their chemical composition, such meteorites are often used as natural models for the Earth's metallic core.