Temperature and Ice Caps on Mars
The averaged temperature on Mars (about -63°C) is actually considerably lower than the one on Earth (+15°C). But the variation of temperature along the seasons are really important. The gradient of temperature between the dayside and the nightside is also important. The temperature can be:
This is mainly due to the fact that the greenhouse effect on Mars is weak and that the Martian soil store very few energy. Temperature also fluctuate with the amount of dust in the atmosphere of Mars.
Such cold conditions mean that it is no surprise that one can see ice caps on both poles, even with the smallest telescopes. But this dry ice mainly consists of carbon dioxide and not water as on Earth. This carbon dioxide ice comes from the atmosphere and freezes in winter as the solidification of the carbon dioxide is -125°C.
The size of the polar caps varies according to the season: