Astronomy Practice Exam

Mars' temperatures near its poles in winter can drop to extremely low levels, with recorded temperatures as frigid as about -195 degrees Fahrenheit. This extreme cold is primarily due to its thin atmosphere, which is composed mostly of carbon dioxide and does not retain heat well. During the winter season, polar ice caps are formed primarily of water and CO2 (dry ice), and as the polar night sets in, the lack of sunlight contributes to these harshly cold temperatures.

The precise measurements of -195 degrees Fahrenheit reflect the significant contrast between Mars and Earth, particularly in terms of atmospheric pressure and composition. While Earth's atmosphere helps to moderate temperatures, Mars’ minimal atmosphere leads to drastic temperature fluctuations, especially in the polar regions during winter.