Lead researcher Sarah Steele and her team utilized advanced simulations and computer modeling to analyze the age of Mars' global magnetic field, known as the dynamo.

Researchers at Harvard's Paleomagnetics Lab have made significant strides in understanding Mars' magnetic history by simulating the cooling and magnetization of large impact basins.

The study builds on earlier research, including the analysis of the Martian meteorite Allan Hills 84001, which provided evidence of magnetic field reversals and suggested a longer-lasting magnetic field.

Previously, scientists estimated that Mars' global magnetic field ceased around 4.1 billion years ago, based on the lack of magnetic records in impact rocks from that era.

The Martian geodynamo, responsible for its magnetic field, cooled rapidly due to heat loss, leading to a cessation of convection and a weakened magnetic field.

Their findings suggest that Mars' magnetic field may have persisted until approximately 3.9 billion years ago, indicating a longer period for potential habitability than previously believed.

This extended duration of the magnetic field could reshape scientists' understanding of atmospheric loss on Mars, impacting estimates of its past conditions and the presence of water.

If accurate, the persistence of Mars' magnetic field could imply that a habitable environment existed during the time when water was present on its surface.

Understanding Mars' magnetic field is crucial for uncovering the planet's ancient history and its potential for past life, emphasizing the importance of planetary magnetic fields in the broader context of solar system history.

The research team posits that the weak magnetic signals observed in impact craters could be attributed to magnetic pole reversals occurring during the dynamo's existence, rather than a complete shutdown.

The research was led by Sarah Steele, a graduate student, and senior author Roger Fu, a professor at Harvard, highlighting the collaborative effort in advancing our understanding of Mars.

These findings were published in August 2024 in the journal Nature Communications, challenging earlier estimates and opening new avenues for research into Mars' magnetic history.