Researchers from Harvard University (USA) have discovered a “life era” on Mars that lasted for 200 million years.
According to a study published in the scientific journal Nature Communications, a team led by Dr. Sarah Steele from Harvard University found that Mars' magnetic field may have lasted 200 million years longer than previously estimated.
This finding presents a crucial factor in the evolution of extraterrestrial life.
Previous studies suggested that Mars was initially similar to Earth, with abundant liquid water and a strong magnetic field capable of shielding life from cosmic radiation.
According to Space.com, planetary scientists previously believed that Mars' global magnetic field had disappeared more than 4.1 billion years ago due to the formation of large impact basins during the heavy bombardment period between 4.1 and 3.7 billion years ago.
However, Dr. Steele and her colleagues argue that these signs may have been misinterpreted.
Their analysis of fragments from the famous Martian meteorite Allan Hills 84001 provides evidence of magnetic reversals recorded in ferromagnetic minerals.
A computer model supports this hypothesis, suggesting that the absence of a magnetic field at the time of the impact basin formations was not due to the field shutting down, but rather a temporary weakening caused by magnetic pole reversals—a phenomenon that has also occurred multiple times on Earth.
The study also indicates that with these new data, Mars' magnetic field must have persisted until at least 3.9 billion years ago.
This is significant because these additional 200 million years overlapped with the period when the planet's river systems and oceans were still abundant with water.
Thus, life on Mars had an extra 200 million years in a favorable environment, potentially allowing it to evolve further than previously assumed.
Moreover, if the magnetic field disappeared later than thought, Mars' atmosphere could have remained similar to Earth's for a much longer period.
“This means that scientists' timeline of environmental changes on Mars may need some refinement,” the research team stated.
