What is one hypothesis for why the crust in the northern hemisphere of Mars is thinner and lower than that in the southern hemisphere?
A) a giant impact blasted away crust from the northern hemisphere
B) it once hosted an ocean of water which eroded away the crust
C) tectonic activity caused the southern hemisphere to rise up above the level of the northern hemisphere
D) massive "marsquakes" caused the northern hemisphere to subside

Question

Quizplus · Accepted Answer

The hypothesis that a giant impact blasted away crust from the northern hemisphere of Mars is one explanation for the observed dichotomy in crustal thickness and elevation between the northern and southern hemispheres. This impact would have removed a significant portion of the crust, leaving the northern hemisphere thinner and lower.

What Is One Hypothesis for Why the Crust in the Northern