Actual ancient magnetization of the lunar crust is unknown

Determine the actual ancient remanent magnetization of the lunar crust in the Chang’e‑5 landing region (northern Oceanus Procellarum) in order to replace the assumption of saturation remanent magnetization used in forward modeling of surface magnetic anomalies and thereby more accurately quantify any local crustal contribution to the ~2–4 μT paleointensities recorded by Chang’e‑5 basalt clasts.

Background

To assess whether local crustal magnetic anomalies could account for the microtesla paleointensities observed in Chang’e‑5 basalt clasts, the authors performed forward modeling of surface magnetic anomalies for plausible crustal structures near the landing site. Because the true ancient magnetization of the crust is not established, they assumed saturation remanent magnetization values to compute an upper bound on possible anomalies.

This assumption acknowledges that the actual ancient remanence of the lunar crust remains unknown, limiting the precision of the modeled contribution of crustal fields. Establishing realistic magnetization values for the crust in this region would allow more accurate evaluation of local anomaly effects versus a core dynamo origin for the measured paleointensities.