The number of mysteries in our solar system is staggering and a new mystery very close to home has a new possible solution. Scientists and astronomers have long wondered why the two sides of our moon are so different. The side of the moon that faces the earth is vastly different than the side of the moon often called the dark side that we never see.
The dark or far side of the moon is made up of tall mountains while the near side of the moon is covered with plains of volcanic rock called maria. The far side of the moon has few maria plains. The near side also has topography mostly low and flat whereas the far side is on average 1.2 miles higher than the near side. New computer simulations are now hinting that our moon may be the result of a collision with a smaller moon at some point early in the life of our solar system.
The simulations suggest that a second much smaller moon orbited the earth and collided with the moon we see today. The second moon is thought to have been only 4% of the current moon's mass and about 750 miles wide. That would make it one-third of the moon's diameter. The highlands on the far side of the moon in this theory are thought to be the left over crust and material from the second moon after the collision.