Spend a day on Mercury
Cutting through a surface pitted with impact craters is the magnificent Victoria Rupes on Mercury, the closest planet to our sun. Rupes are escarpments, or slopes, that can form when a planet’s surface is compressed. On Earth, compression is created when slabs of the planet’s outer shell slide around, pulling apart in some areas and pushing together in others. When one slab of rock is pushed over another, a thrust fault is formed. On Mercury, compression is caused by the planet shrinking as it cools over time, cracking and contracting its brittle surface.
Ridges and cracks
Ridges and cracks are found on planets and moons across the solar system, where forces pull the ground apart or press it together. Their presence tells us that landscapes are active, responding to changes in their environment such as heating and cooling or pushing and pulling. Looking at these pictures from around the solar system, do you see a crack or ridge in the landscape?