Moon lost its magnetic field billions of years ago which was probably even stronger than the Earth’s field, a study said trying to pin the timing of its end.
Moon lost its magnetic field billions of years ago which was probably even stronger than the Earth’s field at present, a study said. Researchers, in the new analysis, tried to pin down the timing of the end of the lunar dynamo, which was active during the period 4.25 to 3.56 billion years ago.
The intensity of the present-day magnetic field across much of the lunar surface indicates that the moon currently does not have a global magnetic field. But the Apollo samples from the moon were analysed and its paleomagnetic measurements established that it generated a core dynamo with surface field intensities measuring to several tens of microtesla.
Core crystallisation phenomenon
A team of researchers from the Massachusetts Institute of Technology (MIT), with the help of the National Aeronautics and Space Administration (NASA), found out that the lunar dynamo ended around one billion years ago. According to the study, an important mechanism of core crystallisation favoured the lunar dynamo. The liquid core’s electrically charged fluid was buoyantly stirred due to the crystallisation of the moon’s inner core and produced the dynamo.
Earlier, scientists had discovered signs of a strong magnetic field in lunar rocks as old as 4 billion years and measuring around 100 microtesla, which is almost twice the present-day Earth’s magnetic field. Later, Weiss’s team studied the sample collected from the Appollo mission and found a much weaker magnetic field.
Source - Republic World