Which of these were observed from Earth, prior to spacecraft missions to Mars?
A)seasonal changes in the polar caps
B)eruptions of Mount Olympus
C)dust storms capable of covering the entire planet
D)Both A and C are correct.
E)All of the above are correct.

Question

Quizplus · Accepted Answer

Seasonal changes in the polar caps and dust storms capable of covering the entire planet were both visible from Earth prior to spacecraft missions to Mars. Eruptions of Mount Olympus were not observable from Earth as Mount Olympus Mons is a volcano on Mars. Prior to spacecraft missions to Mars, both seasonal changes in the polar caps and dust storms capable of covering the entire planet were observed from Earth. However, eruptions of Mount Olympus were not observed until the first spacecraft missions to Mars.

Which of These Were Observed from Earth, Prior to Spacecraft