the highest region of the atmosphere, where the air density is so low that a fast-moving air molecule is more than 50 percent likely to escape from the atmosphere instead of hitting other molecules.
更多exosphere例句
In the shed on the left is Orion, which is a two-stage rocket for deep penetration into the exosphere.
His instruments told him they were breaching the exosphere, where molecular matter had almost ceased to exist.
The atoms of the exosphere were lonely, uncrowded, isolated particles.