A groundbreaking study has revealed that Earth’s current magnetic field may have been remarkably similar to what it was a staggering 3.7 billion years ago. This discovery, made possible through the analysis of ancient rocks, provides scientists with their oldest estimates of our planet’s magnetic field strength. The study, published in the Journal of Geophysical Research, sheds light on the crucial role the magnetic field has played in shielding Earth from cosmic radiation and the Sun’s solar wind, enabling the emergence and evolution of life on our planet.