World Mourns Loss of Skier. U.S. Freeskiing, and the entire U.S. Ski and Snowboard Association family, joined the Park City community in mourning the passing of Sam Jackenthal, a wonderful young man and a remarkable athlete.
The least dense layer of the earth is the Crust , the mantle is second densest , whereas the core is the most dense layer of the earth
Most of the earth's atmosphere (80 to 90%) is found in the troposphere, the atmospheric layer where we live. This layer, where the earth's weather occurs, is within about 12 km (7 miles) of the earth's surface. The stratosphere goes up to about 53 km (29 miles). Gravity is the reason the atmosphere is more dense closer to the earth's surface. This activity demonstrates the relative thickness of the thin layer that includes the troposphere and stratosphere. This layer is essential to all life on earth.