For more than forty years, scientists believed the Earth’s magnetic field reached a natural limit during the most powerful solar storms. This apparent “saturation” inspired ten competing physical explanations and shaped our understanding of space weather. But a new study argues that the limit never existed. Instead, it may be the product of a subtle statistical bias caused by measurement uncertainty and a phenomenon known as regression to the mean. By correcting for this bias, the researchers recover a simple linear relationship between the solar wind and the Earth’s magnetic response, overturning a long-standing assumption with implications that extend well beyond space physics.
We are delighted to introduce Claire Nichols as the 2026 Johannes Geiss Fellow, whose research explores planetary magnetism and what it can tell us about the deep interiors, atmospheres, and habitability of planets across our solar system and beyond. Based at the University of Oxford, Claire combines a background in Earth Sciences with a fascination for meteorites, the Moon, and the magnetic histories of planets large and small. In this interview, she reflects on her path into space science, explains why invisible magnetic fields matter so much, and shares what she is most excited about during her upcoming stay at ISSI in Bern—alongside her enthusiasm for mountains, chocolate, and the occasional punting mishap.
