what is the thickest part of earths atmosphere
Layers of the Earth-page 4 of 5. The mantle is 84% of the Earth's mass, making it the thickest layer of the earth. We said earlier that it's highly viscous, and it's temperature ranges from 500 degrees Celsius at the crust to 4,000 degrees near the outer core.That means that the coolest part of the mantle is more than five times hotter than boiling water. OUCH!e said earlier that it's highly viscous, and it's temperature ranges from 500 degrees Celsius at the crust to 4,000 degrees near the outer core. That means that the coolest part of the mantle is more than five times hotter than boiling water. OUCH!