A Race
A lesser-known quest was to conquer the subterranean. Soviet and American scientists began organizing experiments in the name of penetrating the Earth’s crust in the late 1950s. This is part of the Earth that stretches as much as 30 miles towards the planet’s center.
The Mantle
The mantle is the dense shell of the Earth giving way to the unexplained inner layer and makes up more than 40 percent of the planet’s mass. This quest led to an enticing journey for researchers and scientists.