The jury is still out on exactly how the Moon formed. The prevailing theory is that a ‘Mars-sized protoplanet’ crashed into teenage Earth and the resulting debris collapsed to form the Moon. Chemical analysis shows that its composition is relatively close to Earth. However, scientists have discovered that rocks in the bright plains (the lunar highlands) actually contain fewer metallic minerals than those found in the darker plains. This only makes sense if the Earth had already formed its core, mantle, and crust before the collision, leaving the Moon devoid of metal. However, rocks found in the darker plains of the Moon contain more metal than those found on Earth (via NASA).
In 2011, NASA launched miniature radio frequency (Mini-RF) aboard the Lunar Reconnaissance Orbiter, which still orbits the Moon today. His original mission was to find ice on the surface, but eleven years later… he found something else.
While measuring an electrical property in the lunar soil inside craters – called the dielectric constant – the Mini-RF discovered that this property increased in craters 1 to 3 miles wide but remained the same for craters 3 12 miles wide. Essam Heggymission co-investigator, and other scientists believed it was a correlation that had no reason to exist (via NASA).