The composition of the polar ice caps of Mars has been determined by each of the following methods EXCEPT one. Which one has NOT been used?
A)the soft landing of an unmanned space craft at the north pole
B)measuring from orbit the spectrum of sunlight reflected from the poles
C)measuring from orbit the temperature at the poles
D)using infrared cameras to probe the spectrum of the lower layers of the caps

Question

Quizplus · Accepted Answer

As of 2021, no soft landing of an unmanned spacecraft at the north pole of Mars has been conducted to determine the composition of the polar ice caps. However, the other three methods listed (measuring reflected sunlight, measuring temperature from orbit, and using infrared cameras to probe the spectrum) have been used to determine the composition of the ice caps.

The Composition of the Polar Ice Caps of Mars Has