Chapter 17

Front 1

1. Stony meteorites are less commonly collected than iron meteorites because ________________.
A. they break up more readily while passing through the Earth's atmospheric filter
B. those that reach the ground are weathered and destroyed more rapidly
C. they are not as easily recognized
D. All of these are correct.
E. None of these are correct.

Back 1

D. all of these are correct

Front 2

2. Why are there so many more impact craters visible on the Moon than on the Earth?
A. The moon has been hit by many more meteorites than the Earth, particularly the >1 km diameter bodies that create the biggest craters.
B. The moon formed long before the earth formed, so has had more time to be hit by meteorites.
C. The moon is made out of softer rock than the Earth that is more readily deformed when impacted by meteorites.
D. Because of gravitational effects, the moon deflects many of the meteorites that would otherwise hit the Earth.
E. Craters on the Earth can be destroyed by erosion and mountain-building processes, or obscured by vegetation or sedimentation.
F. The period of heavy meteorite bombardment of the Earth occurred only when the planet was very young and entirely molten, so craters were not created.

Back 2

E. Craters on the Earth can be destroyed by erosion and mountain-building processes, or obscured by vegetation or

Front 3

3. When space debris blazes through the Earth's atmosphere as a streak of light or shooting star, it is referred to as a _________________.
A. moonlet
B. falling star
C. sunspot
D. meteor
E. starlet

Back 3

D. meteor

Front 4

4. Asteroids lie mostly ____________________.
A. between Mars and Jupiter
B. between the inner and outer planets
C. beyond Pluto, and in the Van Halen Belt
D. between Mercury and the Sun
E. Both between Mars and Jupiter and between the inner and outer planets are correct.

Back 4

E. Both between Mars and Jupiter and between the inner and outer planets are correct.

Front 5

5. In 1994, the comet Shoemaker-Levy crashed with spectacular results into _______________.
A. Saturn
B. Mars
C. Titan
D. Jupiter
E. Venus

Back 5

D. Jupiter

Front 6

6. The space between Mars and Jupiter is occupied by ________.
A. bolides
B. meteorites
C.asteroids
D. comets
E. ejecta

Back 6

C.asteroids

Front 7

7. Venus resembles Earth in size, density, and distance from the Sun, but has a dense cloud cover of ________.
A. CO2
B. hydrochloric-acid
C. methane
D. ozone
E. hydorgen-sulfide

Back 7

A. CO2

Front 8

8. Evidence for the impact that occurred near Chicxulub, Mexico, includes all but which of the following?
A. quartz grains with shocked crystal structures, indicating a short and violent impact
B. iridium anomaly at roughly 100 sites worldwide in a thin layer of rock 65 million years old
C. sand-sized spherules of minerals suggesting a melting and resolidification of rock
D. large pieces of meteorite found in Mexico
E. The K/T boundary clays have a different composition from clays in the limestone layers above and below it; they might be explained by a mixture of one part asteroid to ten parts Earth crust.

Back 8

D. large pieces of meteorite found in Mexico

Front 9

9. When a meteorite large enough to cause a crater hits the Earth, the size of the impact crater is __________________.
A. smaller than the meteorite
B. perhaps 10-20 times the diameter of the meteorite
C. about the same as the meteorite
D. determined by the angle of impact
E. determined mostly by the rock type at the point of impact

Back 9

B. perhaps 10-20 times the diameter of the meteorite

Front 10

10. Critical evidence for the Cretaceous-Tertiary boundary impact included ___________________.
A. dinosaur fossils worldwide just above the layer of impact debris
B. an iridium anomaly in a thin layer of rock 65 million years old
C. recovery of very large pieces of meteorite
D. discovery of a crater covered by jungle vegetation in Brazil
E. an Iranian deposit of reddish iron bearing strata

Back 10

B. an iridium anomaly in a thin layer of rock 65 million years old

Front 11

11. Likely effects of the Cretaceous-Tertiary boundary impact include all but which of the following?
A. a stratospheric dust cloud that lasted 3-6 months
B. massive fires from the heat of the blast and from molten material
C. oxides of nitrogen formed by the compressive shock wave, forming HNO3 in the atmosphere
D. significant long-term cooling in the oceans but warming in continental areas
E. total extinction of all land animals with a body mass of more than about 10 kg

Back 11

D. significant long-term cooling in the oceans but warming in continental areas

Front 12

12. A major comet or meteorite impact occurred in Mexico at the time boundary between the _________________.
A. Pleistocene and Pliocene
B. Precambrian and Cambrian
C. Cretaceous and Tertiary
D. Pliocene and Miocene
E. Jurassic and Cretaceous

Back 12

C. Cretaceous and Tertiary

Front 13

13. Relatively few impact craters have been discovered on Earth because _________________.
A. most rocks are too resistant to crater
B. the gravitational field is too weak
C. weathering, erosion, and tectonic processes mask them
D. bolides are very rare in this region
E. Jupiter is so large it deflects them away from Earth

Back 13

C. weathering, erosion, and tectonic processes mask them

Front 14

14. Venus resembles Earth in size, density, and distance from the Sun, but has a dense cloud cover of CO2. Its air temperature is _________ that on Earth.
A. warmer than
B. cooler than
C. about the same as
D. there is no air on venus

Back 14

A. warmer than

Front 15

15. The planets and the asteroid belt orbit the Sun ______________________.
A. in a spherical distribution, whereas the Oort cloud of comets orbits in a plane
B. in a spherical distribution similar to that of the Oort cloud of comets
C. in planes tilted at an angle to the plane of the Oort cloud of comets
D. in planes, whereas the Oort cloud of comets has a spherical distribution
E. in orbits nearly identical to the Oort cloud of comets

Back 15

D. in planes, whereas the Oort cloud of comets has a spherical distribution

Front 16

16. Comets are composed of _____________________.
A. ice and rocky debris
B. gas, mostly hydrogen and helium
C. solid rock, mostly andesite
D. electro-magnetic plasma
E. mostly organic material

Back 16

A. ice and rocky debris

Front 17

17. The solar wind is _____________________.
A. what causes visible dust storms on Mars
B. wind blowing on the surface of the Sun
C. wind blowing within the Sun's dense gas below the surface
D. the stream of subatomic particles flying outward from the Sun
E. a blast of sunspot energy

Back 17

D. the stream of subatomic particles flying outward from the Sun

Front 18

18. A comet's tail ____________________.
A. lines up with the solar wind moving outward from the Sun
B. points toward the nearest planet as a result of its gravity
C. is a vapor trail behind a comet that points in the direction from which the comet came
D. always points toward the Sun
E. is composed of smoke from the burning comet

Back 18

A. lines up with the solar wind moving outward from the Sun

Front 19

19. Halley's comet has an average orbital period of __________________.
A. 76 years
B. 1 year
C. 577 years
D. about 10,000 years
E. about 100,000 years, coinciding with average ice-age periods

Back 19

A. 76 years

Front 20

20. The numbers of incoming objects are related to their size:
A. the smaller the meteoroids, the greater their abundance.
B. the larger the meteoroids, the greater their abundance.
C. the number is the same for each size range.
D. the size is inversely proportional to the number

Back 20

A. the smaller the meteoroids, the greater their abundance.

Front 21

21. The world's classic meteorite crater lies on an arid portion of the Colorado Plateau in ____________________.
A. Wyoming
B. Colorado
C. Utah
D. New Mexico
E. Arizona

Back 21

E. Arizona

Front 22

22. Evidence demonstrating that the crater in Arizona formed by meteorite impact includes all but which of the following?
A. The crater is steep-sided and closed.
B. The rim of surrounding rock was created by uplifting the horizontal sedimentary-rock layers of the region and tilting them away from the crater.
C. Little hills of rock outside the crater rim are inverted piles of the rock sequence exposed in the crater walls.
D. Huge blocks of limestone are strewn around outside the crater.
E. A 550-ton spherical piece of nickel-iron metallic meteorite was found in the bottom of the crater.

Back 22

E. A 550-ton spherical piece of nickel-iron metallic meteorite was found in the bottom of the crater.

Front 23

23. The 1-cm-thick clay layer that marks the Cretaceous/Tertiary (K/T) boundary has a high percentage of the element ________ in the clay layer, an enrichment about 300 times greater than the normal abundance.
A. iridium
B. silicon
C. iron
D. oxygen
E. zircon

Back 23

A.iridium