fluid. n. 1. (General Physics) a substance, such as a liquid or gas, that can flow, has no fixed shape, and offers little resistance to an external stress. adj. 2. (General Physics) capable of flowing and easily changing shape.
The thermosphere layer. The thermosphere layer is called the thermal layer as it is the hottest layer of the atmospheric envelope . It is the fourth layer of the atmospheric envelope, The temperature of the thermosphere layer increases with a high rate as we go up until it reaches 1200 degree Celsius
The temperature of the Exosphere ranges from 300 degrees Celsius to 1700 degrees Celsius.