Chapter 7. Earth and The Terrestrial Worlds. Principles of Comparative Planetology. Comparative Planetology is the study of the solar system through examining and understanding the similarities and differences among the planets. Planetary Geology:
Earth and The Terrestrial Worlds
Venus’ surface- atmosphere is not shown. Surface mapped from Megellan spacecraft radar data
Mars Exploration Rover Mission: The Mission
Apollo Lunar Missions (1969-1972)
Mars Pathfinder Mission (1996-1997)
There are four main geological processes
Volcanism conduction and convection.
(Mount St. Helens) conduction and convection.
c) “Sticky” lava makes steep-sloped stratovolcanoes.
Picture by US Geological Survey scientist, Austin Post, on May 18, 1980.
Tectonic Forces at work. conduction and convection.
Comparing Planetary Atmospheres conduction and convection.
Visible Light: Warming the Surface and Coloring the Sky conduction and convection.
Atmospheric gases scatter blue light more than they scatter red light.
Longer wavelength red light is more penetrating
The Greenhouse Effect conduction and convection.
Temperatures of the Terrestrial Worlds conduction and convection.
Aurora Borealis – Norhern Lights near the poles, produces the:
Five Major Processes By Which Atmospheres Lose Gas.
Astronaut explores a small crater
An ancient lava river
Mercury is greater than the escape speed of the planet.(2,440-km radius, 0.39AU from the Sun)
Dust Storm over northern ice cap, is greater than the escape speed of the planet.Mars Global Surveyor
Polar Ice Cap (Mars) Viking Orbiter
Edge of polar ice cap showing layers of ice and dust.
Mars (3,397-km radius, 1.52 AU from the Sun)
Cratering, Volcanism and Tectonics is greater than the escape speed of the planet.
Heavy cratering in Southern Hemisphere
Olympus Mons: – largest shield volcano in the solar system
Martian outflow channels and flood planes is greater than the escape speed of the planet.
Ancient River beds
Outflow channels indicate catastrophic flooding
Water eroded crater
Gullies on a crater wall formed by water flows?
Venus (6,051-km radius, 0.72 AU from Sun) is greater than the escape speed of the planet.
Shield Volcanoes are common
Impact craters on Venus are rare
Fractured and twisted crust
Earth (6, 378 km radius, 1.0 AU from the Sun) is greater than the escape speed of the planet.