Deck 25: Meteorites,asteroids,and Comets

Question 1

A meteor shower is produced when

A) a large number of sporadic meteors are observed.
B) the Earth passes through the asteroid belt.
C) massive particles are carried outward from the sun by the solar wind and enter Earth's atmosphere.
D) the Earth passes through the orbital path of a comet.
E) meteors cause condensation in the upper atmosphere that leads to early morning rains.

Answer 1

the Earth passes through the orbital path of a comet.

Question 2

What evidence exists that some of the asteroids were geologically active?

A) A few of the larger asteroids show small volcanic mountains.
B) The moons of Mars,which are thought to be captured asteroids,show evidence of flooding by lava.
C) The meteorites that are breccias could only have formed in a molten mantle.
D) Spectroscopically,Vesta appears to have regions of small lava flows.
E) Io is very geologically active with sulfur volcanoes.

Answer 2

Spectroscopically,Vesta appears to have regions of small lava flows.

Question 3

An asteroid could produce an iron core and a silicate mantle if it

A) differentiated.
B) outgassed.
C) condensed.
D) accreted.
E) sublimed.

Answer 3

differentiated.

Question 4

If 200,000 asteroids that were each 0.5 km in radius combined to form a single object,what would the radius of the new object be? [This question requires the use of mathematics.]

A) 224 km
B) 29 km
C) 100,000 km
D) 0.224 km
E) 1000 km

Question 5

The diagram below shows the relative size of Earth's moon and the asteroid 10 Hygiea.Based on this diagram,what is the diameter of 10 Hygiea?

A) 460 km
B) 46 km
C) 4600 m
D) 46 m
E) 4600 km

Question 6

The diagram below is a plot of an object's albedo versus its ultraviolet minus visual color (U - V color).In this diagram,which of the asteroids would be most reflective?

A) Object A
B) Object B
C) Object C
D) Object D
E) Object E

Question 7

Uranium,thorium,and the radioactive isotope of potassium cannot supply the heat to melt small planetesimals,but the existence of iron and achondrite (stone)meteorites indicates that some asteroid sized bodies did melt inside.This is thought to be because short lived,intensely radioactive aluminum 26 atoms

A) were much more abundant in the solar nebula at the location where the asteroids formed.
B) were not present in the solar nebula at the location where the asteroids formed.
C) are only found in the outer layers of asteroids and not in the core.
D) are very volatile and evaporated from the asteroids before they could decay.
E) are only found on rocks that formed on the earth and in no other celestial objects.

Question 8

Which of the following could not be caused by the gravitational influence of the planets?

A) Trojan asteroids
B) Kirkwood's gap
C) Hirayama families
D) All of the above were caused by gravitational influence of the planets.
E) None of these were caused by gravitational influence of the planets.

Question 9

The short-period comets do not have randomly oriented orbits because

A) they are affected by the sun's gravity.
B) they are affected by the solar wind.
C) their orbits have been altered by encounters with the planets.
D) their orbits are altered by the drag of their tails in the solar wind.
E) they all were originally objects ejected from the asteroid belt.

Question 10

The diagram below is a plot of an asteroid's albedo versus it ultraviolet minus visual color (U - V color).In this diagram,which of the asteroids is most likely an S-type asteroid?

A) Object 1
B) Object 2
C) Object 3
D) Object 4
E) Object 5

Question 11

A bit of matter that enters Earth's atmosphere and survives to reach the ground is called

A) a meteor.
B) a dwarf planet
C) a meteorite.
D) a minor planet.
E) an asteroid.

Question 12

The iron meteorites

A) represent the largest number of falls.
B) are only found in the Antarctic.
C) are composed of carbonaceous chondrites.
D) are responsible for most of the meteor craters on the surface of the moon.
E) appear to have formed from the interiors of molten objects of planetesimal size.

Question 13

The Widmanstätten patterns found in some meteorites show that the material

A) cooled very slowly.
B) cooled very rapidly.
C) was never heated to the point of being molten.
D) was molten just before it entered Earth's atmosphere.
E) is composed primarily of organic compounds.

Question 14

The Allende meteorite is important because

A) it is the largest iron meteorite ever found.
B) its composition suggests that it is very old and unchanged from when it formed.
C) it is the object that produced the Tunguska event.
D) it contains the most well defined Widmanstätten patterns ever found.
E) it is the only meteorite to ever strike and kill a person.

Question 15

Uranium,thorium,and the radioactive isotope of potassium cannot supply the heat to melt small planetesimals,yet are sufficient to melt the interior of Earth.This is because these elements

A) decay slowly,and the heat generated must be trapped by a thick crust if it is to melt the interior.
B) were not present in the solar nebula at the location where the asteroids formed.
C) are only found in the outer layers of asteroids and not in the core.
D) are very volatile and evaporated from the asteroids before they could decay.
E) are only found on rocks that formed on the earth and in no other celestial objects.

Question 16

The gas tail of a comet always

A) trails behind the head along the orbital path.
B) extends ahead of the head along the orbital path.
C) points toward the sun.
D) points away from the sun.
E) points perpendicular to the orbital path.

Question 17

A chondrite is a meteor that has

A) never been heated.
B) been heated but never very hot.
C) been heated to a high temperature.
D) been melted.
E) entered Earth's atmosphere but will be destroyed before reaching the ground.

Question 18

Most of the asteroids orbit the sun 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 19

An asteroid has an orbital period around the sun of 5.2 years.How far from the sun is this asteroid? [This question requires the use of mathematics.]

A) 5.2 AU
B) 10.4 AU
C) 27.0 AU
D) 3.0 AU
E) 2.3 AU

Question 20

Currently the most accepted explanation of the Tunguska Event is the explosion of

A) a German U-2 rocket.
B) an iron meteor just above the surface of the earth.
C) a stony asteroid just above the surface of the earth.
D) a mini black hole in the earth's atmosphere.
E) an alien space craft as it crashed to earth.

Question 21

The ____ is a disk-shaped cloud of icy bodies believed to extend from about 40 AU out to 100 AU.It is believed that short-period comets originate from this region.

A) Oort cloud
B) Widmanstätten cloud
C) Apollo-Amor
D) Kirkwood region
E) Kuiper belt

Question 22

During the Cretaceous extinction 65 million years ago ____ percent of the species on Earth died out.

A) 1
B) 7.5
C) 75
D) 750

Question 23

The Cretaceous extinction 65 million years ago is thought to have been caused by

A) the impact of a small asteroid.
B) the impact of one of the Jovian planets.
C) the impact of one of the terrestrial planets.

Question 24

What type of physical process has led to the different types of meteorites that we see today?

A) Nuclear Fusion
B) Accretion
C) Condensation
D) Differentiation

Question 25

One theory suggests that the bodies in the Oort cloud formed

A) near the present orbits of the terrestrial planets.
B) near the present orbits of the Jovian planets.
C) at high temperatures.
D) from silicate materials.
E) in outside of the original solar nebula.

Question 26

One important way a major impact on Earth is thought to have triggered extinction of many species is because

A) the fragments hit animals on their heads,killing them.
B) the Earth's moon was thrown out of its orbit.
C) of changes to the world-wide climate.
D) Wrong! Major impacts are not thought to have triggered extinctions.

Question 27

The impact of a large comet with Earth has been suggested to have caused the extinction of the dinosaurs.The impact site of this comet is in or near

A) Iowa
B) Hudson Bay
C) Crater Lake,Oregon
D) Canberra Australia
E) Chicxulub Mexico

Question 28

How is the coma of a comet produced?

A) Rocky material breaks off from the comet to form the coma.
B) The coma is a cloud of particles that the comet has swept up in its orbital path.
C) Ices vaporize to become gas that form around the comet nucleus.
D) Particles in the solar wind get caught in the comet's magnetic field to form the coma.

Question 29

The dust thrown up into the stratosphere by the impact of an asteroid can

A) heat the surface of the earth.
B) cool the surface of the earth.
C) Wrong.There will be no effect.

Question 30

Two major kinds of meteorites are

A) iron and stony.
B) hydrogen and helium.
C) Jovian and terrestrial.
D) lunar and solar.

Question 31

The Tunguska impact in 1908 in Russia left behind

A) a giant crater.
B) extinction of many life forms.
C) no crater.

Question 32

Sungrazers are

A) asteroids located inside the orbit of Mercury.
B) meteorites that have a composition very similar to that of the sun.
C) asteroids removed from Kirkwood's gap by the influences of the sun and Jupiter.
D) comets that get very close to the sun.
E) cattle that only feed when the sky is clear.

Question 33

If a large comet struck the Earth,

A) I & IV
B) II & III
C) I,II,& III
D) I,II,& IV
E) II,III,& IV

Question 34

The type I,or gas,tail of a comet

A) is smooth and featureless with a spectrum identical to that of the sun.
B) is present even when the comet is located in the region of the Kuiper belt.
C) is unaffected by the magnetic field of the sun.
D) always points toward the sun.
E) is streaked and shows emission lines of ionized atoms.

Question 35

What characteristic of long period comets suggest they come from the Oort cloud?

A) They have longer Type II tails than short period comets.
B) Their orbits have random inclinations with respect to the ecliptic plane.
C) Their orbits are nearly circular.
D) They tend to appear larger in diameter than short period comets.

Question 36

Which of the following is evidence for the connection between comets and meteor showers?

A) Meteor and comets have the same appearance in the sky.
B) Meteor showers always occur when a comet is visible.
C) Meteor showers always occur 6 months after a comet passes Earth.
D) Meteor showers are a predictable,annual event.

Question 37

Comet Hyakutake 1995 B2 was observed on the night of March 25,1996,with a tail that extended 20 $\degree$ .At this time the comet was 0.10 AU from Earth.What is the minimum length of the tail in AU? [This question requires the use of mathematics.]

A) 0.1 AU
B) 0.005 AU
C) 1.1 AU
D) 20 AU
E) 0.03 AU

Question 38

The density of Comet Halley was found to be about 0.2 g/cm³.This implies that Comet Halley

A) is composed of about 50% rock and 50% frozen water and methane.
B) is loosely packed ices with a small amount of rocky material.
C) formed in the inner solar system and was ejected by Jupiter to the Kuiper belt.
D) is really an S-type asteroid.
E) was once a moon of Neptune and was ripped away by a large impact.

Question 39

The largest object orbiting between Mars and Jupiter is _______which is _________..

A) Ceres; an asteroid
B) Ceres; a dwarf planet
C) Pluto; an asteroid
D) Pluto; a dwarf planet

Question 40

A large iron asteroid striking the earth can create a(n)

A) large crater.
B) ice cap.
C) large ocean.
D) Wrong.There will be no effects.

Question 41

The existence of the Oort cloud cannot be confirmed observationally from Earth because the objects are too small.

Question 42

The Kirkwood's gaps in the asteroid belt are caused by orbital resonances with Mars.

Question 43

No asteroids have orbits that cross the Earth's orbit.

Question 44

Some asteroids show evidence of surface activity such as lava flows.

Question 45

Iridium is more common in meteorites than in the crust of the Earth.

Question 46

The tail of a comet always points toward the sun.

Question 47

Achondrites are rich in volatiles.

Question 48

Asteroids are discovered by their

A) great gravitational effect on Mars' orbit
B) great gravitational effect on Jupiter's orbit
C) orbital motion around the planet Venus in photographs
D) orbital motion among the stars in successive images

Question 49

The meteors in meteor showers are believed to be the debris left behind in comet orbits.

Question 50

Carbonaceous chondrites have been heated to high temperature at least once since they formed.

Question 51

The type I tail of a comet shows a spectrum of bright lines on a dark background of space (an emission line spectrum).From this,one can conclude that the tail contains

A) dust.
B) thin gas.
C) no atoms at all,just empty space.
D) the spectrum does not tell which of the above is true.

Question 52

The majority of meteorite finds are iron meteorites.

Question 53

The solid nucleus or head of a comet is about the size of

A) Jupiter
B) the moon
C) Earth
D) much larger than any of the above
E) much smaller than any of the above

Question 54

The dirty snowball theory suggests that the head of a comet is composed of ices.

Question 55

Meteorites seem to come from both the asteroid belt and the comets.

Question 56

Sungrazers are comets that come very close to the surface of the sun.

Question 57

The type II tail of a comet shows a spectrum of absorption lines on a bright background (like the Sun's spectrum).From this,one can conclude that the tail contains

A) dust.
B) thin gas.
C) no atoms at all,just empty space.
D) the spectrum does not tell which of the above is true.

Question 58

Meteors strike the Earth's atmosphere every day.

Question 59

Which one of the solar system objects below has the smallest mass?

A) a comet
B) Jupiter
C) Mars
D) our moon
E) Venus

Question 60

Jupiter was probably influential in preventing the formation of a planet at the present location of the asteroid belt.

Question 61

Long-period comets are believed to originate in the ____________________.

Question 62

____________________ is a region of the asteroid belt where very few asteroids are found due to gravitational resonance with Jupiter.

Question 63

The fact that more iron meteorites are found than any other kind is a selection effect.

Question 64

Widmanstätten patterns are found in ____________________ meteorites.

Question 65

Meteors seen during a meteor shower appear to come from a point in the sky called the ____________________.

Question 66

The ____________________ of a comet can be up to a million kilometers in diameter.

Question 67

A(n)____________________ occurs when a bit of material enters Earth's atmosphere and becomes incandescent due to friction with the atmosphere.