arXiv · 2511.21884
Null Results, Real Learning: Geomagnetic Response to an X1.8 Solar Flare with Research-Grade and Smartphone Magnetometers in a Citizen-Science Classroom Activity
Abstract
Introductory college Earth and space science courses offer rich opportunities for citizen science projects. One especially compelling context is Earth's geomagnetic field: a self-excited dynamo in the liquid outer core generates a global field that couples Earth's interior to solar forcing, providing a natural laboratory for space weather education. We tested the viability of smartphone magnetometers for quantitative monitoring during the 4 November 2025 X1.8 solar flare, linking planetary magnetism, space weather, and authentic undergraduate research. Co-located observations were obtained with a Geometrics G-857 proton-precession magnetometer and tri-axial smartphone sensors logging via Physics Toolbox in a course-based undergraduate research experience (CURE) emphasizing the Nature of Science (NOS). Fourteen one-minute paired averages spanning 17:27-17:40 UT revealed a systematic smartphone bias of about 630 nT (95% confidence interval 550-710 nT) relative to the G-857 and a weak negative correlation (r ~ -0.4). Smartphone magnetometers thus lack the precision and calibration stability needed for nanotesla-scale flare signatures but remain valuable as pedagogical and engagement tools. We frame smartphones within a tiered instrumentation ladder linking research-grade observatories, intermediate-cost community magnetometers (for example, HamSCI Personal Space Weather Stations), and smartphones as high-engagement entry points to geomagnetic and space weather studies. This hierarchy aligns citizen science with open data protocols and NOS pedagogy, transforming low-cost sensing into epistemically grounded inquiry suitable for introductory college laboratories.
Explore related subjects
Keep this discovery
Roger M. Hart, Lauren E. Messina, Eric A. Schenck, Samantha R. Kaplan, Diego A. Canté, Izaiah Figueroa, Gabriella Sepe, Zavier Lopez, Ryan Ward, Sammy P. Morse, Melanie V. Ramirez, Brady J. Gaulin. 2025-11-26. Null Results, Real Learning: Geomagnetic Response to an X1.8 Solar Flare with Research-Grade and Smartphone Magnetometers in a Citizen-Science Classroom Activity. https://arxiv.org/abs/2511.21884
Cite the original work for its findings. Save a collection to share your selection of sources.