Chapter 7- Terrestrial Planets and the Moon

Question 1

3 Main Shaping Processes

Answer 1

Impacts from space
Volcanism
Tectonics

Question 2

Impacts from Space

Answer 2

Heavy bombardment in the early solar system – lots of cratering on all five bodies (Moon, Mercury, Venus, Earth, Mars)

Question 3

Meteor

Answer 3

Bright streak in the sky when a meteorite passes

Question 4

Meteorite

Answer 4

A fragment of a meteoroid which survives its fall to Earth’s surface

Question 5

Meteoroid

Answer 5

A small body in space

Question 6

Formation of an impact crater

Answer 6

ejecta, rays, crater walls, secondary craters, central peak

Question 7

Why the difference in cratering?

Answer 7

Atmospheres- dense atmospheres prevent most meteoroids from reaching the surface
Evolution of surfaces- some surfaces evolve over time and obliterate signs of impact (Earth- tectonics, Venus- volcanism)

Question 8

Magnetic fields

Answer 8

Earth reverses its magnetic field every hundred thousand years
Moon has no magnetic field due to cooling
Mercury has a weak field- small and slow rotation rate
Venus and Mars have small magnetic fields

Question 9

Planetary interiors

Answer 9

Density calculation- compare measured value of density of surface materials with calculated overall density to see interior density

Seismic waves- p wave, s waves. Both types are sent out during earthquakes, patterns give clue to the interior

Question 10

Tectonics

Answer 10

Plates of rock float on plastic outer mantle, powered by convection currents of hot mantle material. Seafloor spreading pushes plates apart.

No signs or Mercury, Moon, or Venus. Uncertain but unlikely on Mars.

Question 11

Volcanism

Answer 11

Occurs when plates collide and subduct.

Hot spot volcanism- hot spot develops in the crust, magma wells up for long periods of time