Evaluation of the lithospheric magnetic field mapped by the first year of MSS-1 data

The MSS-1 satellite began mapping Earth’s magnetic field in November 2023. Here, we perform a preliminary assessment of the new information provided on Earth’s lithospheric magnetic field from the first 12 months of data from MSS-1. We analyze data from the low-inclination orbital tracks of MSS-1 alongside data collected contemporaneously by the <italic>Swarm</italic> mission, and compare these to models for the lithospheric field from older satellite data and to predictions from models of lithospheric magnetization from tectonic constraints. We find that 1 year of data grouped into geographical bins is sufficient to produce a robust map of lithospheric anomalies. Time series analysis reveals that bins further from the equator arrive at stable values more rapidly, while equatorial regions require 9−10 months of data accumulation for stable signal recovery. The mapped data agree well with older satellite models and with predictions from a lithospheric magnetization model, with the largest mismatches suggesting that models of continental magnetization in particular require further revision. These results demonstrate the value of MSS-1’s unique orbital configuration in complementing existing satellite magnetic field measurements.