Delta ll Launch with Grail to the dark side of the Moon

By understanding the composition of the moon, scientists will be able to infer the internal structure which will allow them to make more accurate assumptions on how structures such as basins and craters were formed.

It is here that the “two moon” theory could be explained. While the side of the moon facing Earth is relatively smooth, the dark side has what is known as the lunar highlands, full of uneven and mountainous formations.

The theory suggests that the second moon, suggested to be 1/3 of the size of the moon, collided with the lunar surface, resulting in the vast surface differences found between the two sides of the moon.