The magnetic field was active by this time, though about 10-50% of its strength today.
# Metadata
Title: Formation of the magnetic field Movietime: 0:54 Geographical Time: 4000 Ma
By this time, Earth's magnetic field was already active — likely at about 10% to 50% of its present-day strength. The formation of the geomagnetic field would have offered early protection from solar and cosmic radiation, contributing to the conditions that made surface water and early life possible.
The geodynamo mechanism, driven by convection in Earth’s liquid outer core, was already in motion. This marked a significant step in the planet’s thermal and chemical evolution.
# See - Earth History Metadata