Temperatures in the Atmosphere
The Viking mission and then the Mars Pathfinder measured the changing temperatures in the atmosphere.
The picture shows that near the surface of Mars the temperatures can be as cold as -150 F (-103 C). Brrrrrr! In the middle of the atmosphere however, the temperature can be a lot colder, -333 F (-203 C)!
In the uppermost reaches of the atmosphere the temperature becomes a lot warmer, 80 F (27 C). 80 degrees sounds almost comfortable! This region of the atmosphere is called the ionosphere, or sometimes the exosphere. It's the region of the atmosphere closest to space and the one which is first exposed to the sun's rays.