Astronomy CH 9 Answers
Rank the five terrestrial worlds in order of size from smallest to largest? | Moon, Mercury, Mars, Venus, Earth |
Under what circumstances can differentiation occur in a planet? | The planet must have a molten interior |
The core, mantle, and crust of a planet are defined by differences in their? | Composition |
What is the most important factor that determines the thickness, and therefore strength, of the lithosphere? | Internal Temperature |
Which internal energy source produces heat by converting gravitational potential energy into thermal energy? | Accretion and Differentitaiton/ both A and B |
Which of the following best describes convection? | It is the process in which warm material expands and rises while cool material contracts and falls. |
The three principal sources of internal heat of terrestrial planets are? | accretion, differentiation, and radioactivity |
Heat escapes from a planet’s surface into space by thermal radiation. Planets radiate almost entirely in the wavelength range of the? | Infared |
Which of the following best describes why the smaller terrestrial worlds have cooler interiors than the larger ones? | They have relatively more surface area compared to their volumes. |
Why does Earth have the strongest magnetic field among the terrestrial worlds? | It is the only one that has both a partially molten metallic core and reasonably rapid rotation |
What are the conditions necessary for a terrestrial planet to have a strong magnetic field? | both a molten metallic core and reasonably fast rotation |
Which two properties are most important in determining the surface temperature of a planet? | distance from the Sun and atmosphere |
How large is an impact crater compared to the size of the impactor? | 10 times larger |
When we see a region of a planet that is not as heavily cratered as other regions, we conclude that? | the surface in the region is younger than the surface in more heavily cratered regions. |
Shallow-sloped shield volcanoes are made from lava that? | has a medium viscosity |
What type of stresses broke Earth’s lithosphere into plates? | the circulation of convection cells in the mantle, which dragged against the lithosphere |
Which of the following describes erosion? | the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather |
Which of the following describes impact cratering? | the excavation of bowl-shaped depressions by asteroids or comets striking a planet’s surface |
How did the lunar maria form? | Large impacts fractured the Moon’s lithosphere, allowing lava to fill the impact basins. |
The Caloris Basin on Mercury covers a large region of the planet, but few smaller craters have formed on top of it. From this we conclude that? | formed toward the end of the solar system’s period of heavy bombardment |
What kind of surface features may result from tectonics? | Valleys, mountains, volcanos, and cliffs/ all of the above |
Olympus Mons is a? | shield volcano on Mars |
Which of the following does not provide evidence that Mars once had flowing water? | the presence of vast canals discovered in the late 1800s by Giovanni Schiaparelli and mapped by Percival Lowell |
How have we been able to construct detailed maps of surface features on Venus? | by using radar from spacecraft that were sent to orbit Venus |
Which of the following show evidence of ancient river beds? | Mars |
What process has shaped Earth’s surface more than any other? | plate tectonics |
How does seafloor crust differ from continental crust? | Seafloor crust is thinner, younger, and higher in density. |
Which of the following is not evidence for plate tectonics on Earth? | existence of volcanoes |
How long, approximately, do geologists estimate it takes for the entire seafloor to be replaced due to plate tectonics? | 200 million years |
Ridges in the middle of the ocean are places where? | hot mantle material rises upward and spreads sideways, pushing the plates apart |
Some of the oldest continental crust on Earth lies in? | Northeastern Canada |
The geysers and hot springs of Yellowstone National Park result from? | plumes of hot mantle rising in a hot spot within a plate. |