Deck 17: Impact of Asteroids and Comets

Question 1

Which of the following would NOT follow impact of a large asteroid on Earth?

A) widespread fires from heat of impact and spray of molten droplets of magma
B) dust and smoke from fires blot out the sun so animals freeze and starve
C) acid rain kills vegetation
D) global wars over food
E) vaporization of much of Earth's oceans

Answer 1

E

Question 2

Near-Earth objects are catalogued by NASA as being larger than __________ in diameter.

A) 10 km
B) 5 km
C) 1 km
D) 2 km
E) 1 m

Answer 2

C

Question 3

How is the tail of a comet oriented? (Which way does it point?)

A) points away from the sun
B) points toward the sun-from its gravitational attraction
C) back from the direction of travel
D) in the direction of its afterburner
E) randomly in space

Answer 3

A

Question 4

What is the relationship between the size of meteorites and the number of a given size?

A) There are an equal number of small, medium, and large meteorites of any given type.
B) There are few small, a moderate number of larger, and many giant meteorites of any given type.
C) There are many small, many medium-sized, but no giant meteorites.
D) There are many small, a moderate number of larger, and few giant meteorites of any given type.
E) There are medium and large meteorites but no small meteorites of equivalent type.

Question 5

An achondrite stony meteorite consists of:

A) mostly olivine.
B) about 1/3 iron, 1/3 olivine, and 1/3 pyroxene.
C) peridotite like Earth's mantle.
D) basalt like Earth's oceanic crust.
E) glass that is high in iron and magnesium.

Question 6

What are comets made of?

A) ice and some rock
B) ice
C) high magnesium and iron rocks
D) nickel-iron
E) close-packed hydrogen

Question 7

On average,how often does a 6-meter diameter asteroid collide with Earth?

A) once every five years
B) once every ten years
C) once every year
D) once every fifty years
E) once every century

Question 8

What is the path of comets around the sun?

A) They range far beyond our solar system and loop past the sun and back into outer space.
B) Their path is the same as Earth.
C) They have a circular orbit around the sun.
D) They orbit the Earth, not the sun.
E) They don't orbit the sun; they are pulled to the sun by its gravity and will crash into it.

Question 9

What is the average size of the head of a comet?

A) 1-2 km across
B) less than 15 km across
C) 50 km across
D) 500 km across
E) 2,500 km across

Question 10

Where do asteroids originate in space?

A) They originate in a belt between Mars and Jupiter.
B) They orbit the Earth.
C) They are fragments of the moon.
D) They follow an eccentric belt around the sun.
E) They are from far outside our solar system.

Question 11

How fast do asteroids travel in space?

A) about 2 to 4 km per minute
B) about 15 to 40 km per minute
C) about 2 to 4 km per second
D) about 15 to 25 km per second
E) about 150 to 400 km per second

Question 12

Which of the following would NOT result from impact of a large asteroid on Earth?

A) energy burns nitrogen with oxygen in Earth's atmosphere (nitric acid/acid rain)
B) tsunami if impact in ocean
C) iridium anomaly
D) impact melts rock and molten droplets spray outward (glass spherules)
E) high radioactivity in the crater

Question 13

A rock that enters Earth's atmosphere and survives to reach the ground is a(n):

A) meteor.
B) meteorite.
C) comet.
D) asteroid.
E) space rock.

Question 14

What are shatter cones?

A) funnel-shaped cones of rock pointing downward (closed downward) and outward
B) streaked cones of rock radiating down (closed upward) and out from the point of impact
C) cone-shaped depressions caused by hypervelocity impact
D) cones of rocks (closed downward) and with vertical axes
E) vertical cracks caused by impact and radiating outward from the point of impact

Question 15

The asteroid belt,orbiting the sun,contains asteroids in a belt between the orbits of:

A) Venus and Earth.
B) Earth and Mars.
C) Jupiter and Saturn.
D) Mercury and Venus.
E) Mars and Jupiter.

Question 16

How fast do comets travel in space?

A) about 2 to 3 km per minute
B) about 60 km per minute
C) about 2 to 3 km per second
D) about 60 km per second
E) about 500 km per second

Question 17

Why would astronomers have difficulty spotting a large incoming asteroid headed for Earth?

A) Coming in directly, it remains in position in space, so astronomers cannot see its trajectory.
B) It comes in so fast that they don't have time to see it.
C) It is dark before becoming heated in Earth's atmosphere.
D) Most of them aren't looking for such an incoming body.
E) It would be too big to see.

Question 18

What natural disasters would NOT be triggered by an impact of a large asteroid on Earth?

A) tsunamis
B) volcanic activity
C) earthquakes
D) flood basalts
E) tornadoes

Question 19

How many times in the last century have meteorites struck people or their houses in North America?

A) none
B) only one
C) only a few (less than 5 or so)
D) about 15
E) about 50 (one every couple of years)

Question 20

What is the largest diameter asteroid impact that leaves an open crater in the ground?

A) about 1 km
B) about 10 km
C) about 100 km
D) about 500 km
E) about 150 km

Question 21

What is Cretaceous-Tertiary boundary clay,and where did it form? Describe the conditions under which it forms and what it looks like.

Question 22

What is the largest asteroid diameter impact that leaves an open crater in the ground?

Question 23

What does the tail of a comet tell you about the direction of travel of that comet?

Question 24

What is the average size of an asteroid?

Question 25

List two secondary (indirect)effects of an impact that would negatively affect humans and other large animals in a major way.

Question 26

What are stony-iron meteorites? Describe the two types of stony-iron meteorites.

Question 27

What is an impact crater?

Question 28

What are meteorites made of?

Question 29

In what plane do asteroids orbit around the sun?

Question 30

What are comets made of?

Question 31

Describe the difference between meteors and meteorites.

Question 32

How fast do comets travel in space?

Question 33

Why do some very large impact craters have a central peak?

Question 34

What is a specific characteristic of an asteroid impact as seen with rocks on the receiving end of the impact? Discuss these characteristics and describe their formation and appearance.

Question 35

What is the most reliable evidence remaining at the site of impact after a large impact?