Caloris Basin,a huge circular region on Mercury surrounded by rings of mountains,appears to have been produced by
A) the impact of a massive object in the early phases of the planet's formation,soon after the initial cratering period.
B) wind erosion from huge atmospheric storms,similar to super-hurricanes on Earth or the Great Red Spot on Jupiter.
C) successive expansion and contraction of the planet's surface by intense solar heating and severe cooling as the planet rotated,causing buckling in a similar way to the formation of the North American Rocky Mountains or the South American Andes.
D) the lava flow from a large and long-lived volcano that formed the mountains in a similar manner to the formation of the Hawaiian Islands on Earth.

Question

Quizplus · Accepted Answer

The presence of a large circular region surrounded by concentric rings of mountains is a classic signature of an impact crater. Other factors supporting the impact theory for the formation of Caloris Basin include the presence of irregularly shaped secondary craters beyond the main basin, and evidence of melted and deformed rocks within the basin. Additionally, the size and morphology of the basin suggest that it was formed during a period of intense bombardment in the early solar system, consistent with the timing of other large impact events on Mercury and other rocky planets.

Caloris Basin,a Huge Circular Region on Mercury Surrounded by Rings