PLANETARY GEOLOGY

Discuss the factors that affected the geologic processes and formations of the planets Outline the information in the 6 slides Use Chapter 9, sections 9.1 and 9.2 to add further detail. Highlight the detail. Refer to your vocabulary to be sure you understand the concepts PLANETARY GEOLOGY

Differentiation Gravity pulled denser materials to the center. Inside the planets are layers controlled by density. Core highest density iron & nickel Mantle moderate density of minerals of silicon and oxygen and other elements Crust/Lithosphere: Lowest density rigid rock “floats” on the softer mantle The thickness of each layer varies with each planet.

PLANETARY GEOLOGY Geological Activity comes from: Heat of Accretion of colliding planetesimals Heat from differentiation Heat from radioactivity Interiors cool off by Convection Conduction Radiation The smaller the planet the faster it cools

PLANETARY GEOLOGY Planetary surfaces are shaped by Impact Cratering Volcanism Tectonics Erosion Convection currents move the tectonic plates and create geologic features

PLANETARY GEOLOGY If a planet is too small like Mars or Mercury or The Moon, the interior will cool too rapidly to have volcanism and tectonics.

 Other Factors of Planetary Geology: Distance from the Sun PLANETARY GEOLOGY Planets too close lose their atmosphere and are too hot for precipitation to cause erosion Planets too far away are too cold for evaporation and condensation for cloud formation. No weather and no erosion

PLANETARY GEOLOGY Planetary Rotation The faster the rotation the more rapid the wind and weather and erosion Earth rotates on its axis every 24 hours while Venus takes 234 days.