Ancient quartz crystals recently discovered in South Africa by researchers from the University of Rochester have revealed new information about the history of Earth's magnetic field. By studying microscopic metals within the 3.5-billion-year-old crystals, researchers determined that Earth must have already possessed a weak magnetic field at the time the crystals formed. The young magnetic field would have provided the planet protection from damaging solar emissions, fostering a more hospitable environment where life could eventually exist.