Planetary Magnetic Fields: The Moon

• Lunar magnetic field is 10⁷ times weaker than that of the Earth, indicating it lacks an internal dynamo…..

Why? 

• Likely due to slow the moon's rotation and apparent lack of fluid core.  The moon is small, and cooled off and solidified early in its history.

Additionally

• Localized regions of higher magnetic fields have been found.
• The Solar wind directly impacts the surface (no magnetic field to protect it).  This creates a plasma void in the plasma umbra, which is perhaps the best vacuum in the solar system!)