If we take a compass to the moon today, it won’t work because the moon doesn’t have a magnetic field. This is not always the case. Scientists at the Massachusetts Institute of Technology have determined when the moon’s liquid core, which generates a magnetic field, will die. Scientists say that at some point in the lunar’s life cycle billions of years ago, its magnetic field may be stronger than that of today’s Earth.
At some point in the lunar’s life cycle, the moon’s magnetic field and the moon’s liquid core movement, which produces it, disappear. Scientists at the Massachusetts Institute of Technology have set the extinction of the moon’s liquid core about a billion years ago. The findings also support a theory of late-stage drivers of the moon’s liquid core movement. This theory is the core crystallization.
As the core crystals, the scientists say, the current in the liquid core is strongly stirred to produce magnetic force. The team says they found that the moon’s magnetic field ended between 1 and 1.5 billion years ago. Before it was terminated, it operated in a way similar to the Earth’s liquid core.
By figuring out when the magnetic field ends, the team says, it can be found to determine the cause of the moon’s liquid core movement. The team studied lunar samples collected by Apollo-era astronauts. Rocks ejected early in the lunar life cycle have microscopic particles aligned with the moon’s magnetic field, thus preserving the record of that magnetic field.
The team says the moon’s history over the past 3 billion years is a mystery because its rock records are so small. Scientists believe that about a billion years ago, the moon had a huge impact, melting rocks and cooling them back, leaving many of the ancient magnetic records missing. The rocks after the impact have a random orientation, indicating that there is no magnetic field. The radiometric dating of the rock determines when the magnetic field will end.