Question 1

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

Accepted Answer

Large pieces of meteorite have not been found in Mexico. The impactor that caused the Chicxulub crater is believed to have been vaporized upon impact and the resulting debris scattered over a wide area. The impact was powerful enough to cause shocked quartz, iridium anomalies, and the formation of spherules and unique clays, all of which have been identified as evidence for the impact.

Question 2

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

Accepted Answer

The correct answer is D because the Cretaceous-Tertiary boundary impact caused significant long-term warming in both the oceans and continental areas.

Question 3

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

Accepted Answer

Weathering, erosion, and tectonic processes constantly modify the Earth's surface, erasing many impact craters over time. Additionally, the Earth's atmosphere is thick enough to burn up and break apart smaller bolides, preventing them from creating visible impact craters. Finally, bolides that do hit the Earth are often obscured by features like oceans or forests, making them difficult to discover. As a result, relatively few impact craters have been identified on Earth compared to many other planetary bodies in the solar system.

Question 4

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

Accepted Answer

Comets are composed of ice, gases (such as water vapor, carbon dioxide, and methane), and varying amounts of rocky debris.

Question 5

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

Accepted Answer

The space between Mars and Jupiter is known as the asteroid belt and is occupied by countless asteroids, also known as minor planets or planetoids. Therefore, the best choice is C) asteroids.

Question 6

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

Accepted Answer

The planets and the asteroid belt orbit the Sun in roughly the same plane known as the ecliptic plane, whereas the Oort cloud of comets is thought to have a roughly spherical distribution of orbits around the Sun. Therefore, the correct choice is D - in planes,whereas the Oort cloud of comets has a spherical distribution.

Question 7

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

Accepted Answer

The comet Shoemaker-Levy crashed into Jupiter in 1994, creating a series of spectacular explosions and leaving dark scars on the planet's surface.

Question 8

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

Accepted Answer

This is based on the concept of the size-frequency distribution, which states that the abundance of small meteoroids is higher than that of larger ones. This is because smaller meteoroids are more numerous in the asteroid belt and Kuiper belt, while larger objects are rarer.

Question 9

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

Accepted Answer

The major comet or meteorite impact occurred in Mexico at the time boundary between the Cretaceous and Tertiary periods, also known as the K-T boundary. This event is believed to have contributed to the extinction of the dinosaurs and many other species.

Question 10

Venus resembles Earth in size,density,and distance from the Sun,but has a dense cloud cover of CO_2. 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

Accepted Answer

Venus has a thick atmosphere made mostly of carbon dioxide with clouds of sulfuric acid. The greenhouse effect of the carbon dioxide atmosphere traps heat and makes Venus' surface temperature an average of 864 degrees Fahrenheit (462 degrees Celsius), which is much warmer than Earth's temperature.

Question 11

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

Accepted Answer

A comet's tail aligns with the solar wind because the solar wind, which is a stream of charged particles ejected from the upper atmosphere of the Sun, pushes dust and gas away from the comet's nucleus, forming the tail that always points away from the Sun.

Question 12

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

Accepted Answer

The iridium anomaly in a thin layer of rock 65 million years old provided critical evidence for the Cretaceous-Tertiary boundary impact, as iridium is rare in the Earth's crust but abundant in meteorites.

Answer: A 
 Dinosaur fossils worldwide just above the layer of impact debris also provided important evidence for the Cretaceous-Tertiary boundary impact. The extinction of the dinosaurs and many other species at this time is thought to be linked to the impact.

Answer: D 
 The discovery of a crater covered by jungle vegetation in Brazil provided further evidence for the Cretaceous-Tertiary boundary impact. This crater, known as the Chicxulub crater, is believed to be the site of the impact that caused the mass extinction.

Therefore, the best choices are B and A.

Question 13

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

Accepted Answer

The asteroid belt, which contains most asteroids, is located between Mars and Jupiter, effectively separating the inner planets (Mercury, Venus, Earth, and Mars) from the outer planets (Jupiter, Saturn, Uranus, and Neptune). This makes both statements correct.

Question 14

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 choices are correct
E)None of these choices are correct

Accepted Answer

Stony meteorites are less commonly collected than iron meteorites because they break up more readily while passing through the Earth's atmospheric filter, those that reach the ground are weathered and destroyed more rapidly, and they are not as easily recognized. Therefore, all of these choices are correct.

Question 15

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

Accepted Answer

Halley's Comet has an average orbital period of approximately 76 years.

Question 16

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

Accepted Answer

When a meteorite large enough to cause a crater hits the Earth, the size of the impact crater is generally around 10-20 times the diameter of the meteorite. The exact size of the crater depends on various factors such as the angle of impact, speed, and composition of the meteorite and the target surface. However, on average, the size of the crater is proportional to the energy of the impact, which is determined by the mass and velocity of the meteorite.

Question 17

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)hydrogen-sulfide

Accepted Answer

Venus has a thick and dense cloud cover composed of carbon dioxide (CO2). This cloud cover creates a strong greenhouse effect on Venus, making it the hottest planet in our solar system with an average surface temperature of about 460 degrees Celsius (860 degrees Fahrenheit). Other gases present in the cloud cover include nitrogen and sulfur dioxide, but CO2 is the primary component.

Question 18

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

Accepted Answer

The solar wind is the stream of subatomic particles (mostly protons and electrons) that fly outward from the Sun and pervade the entire solar system. It is responsible for phenomena such as aurorae and can affect the behavior of spacecraft and satellites in orbit around Earth.

Question 19

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

Accepted Answer

When space debris enters the Earth's atmosphere and forms a streak of light, it is referred to as a meteor or a shooting star. Moonlet and starlet are not used in this context, and sunspot refers to a dark spot on the sun's surface. "Falling star" is a common term that is used interchangeably with meteor, but it is not a scientific term.

Question 20

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

Accepted Answer

Craters on Earth are often erased or obscured over time due to erosion, tectonic activities, and other geological processes, as well as by vegetation growth and sedimentation, whereas the Moon lacks these active processes, preserving its impact craters.

Quiz 17: Impacts With Space Objects

Evidence for the impact that occurred near Chicxulub,Mexico,includes all but which of the following?

Likely effects of the Cretaceous-Tertiary boundary impact include all but which of the following?

Relatively few impact craters have been discovered on Earth because _______________.

Comets are composed of ___________________.

The space between Mars and Jupiter is occupied by ______.

The planets and the asteroid belt orbit the Sun ____________________.

In 1994,the comet Shoemaker-Levy crashed with spectacular results into _____________.

The numbers of incoming objects are related to their size:

A major comet or meteorite impact occurred in Mexico at the time boundary between the _______________.

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 comet's tail __________________.

Critical evidence for the Cretaceous-Tertiary boundary impact included _________________.

Asteroids lie mostly __________________.

Stony meteorites are less commonly collected than iron meteorites because _______________.

Halley's comet has an average orbital period of ________________.

When a meteorite large enough to cause a crater hits the Earth,the size of the impact crater is ________________.

Venus resembles Earth in size,density,and distance from the Sun,but has a dense cloud cover of ______.

The solar wind is ___________________.

When space debris blazes through the Earth's atmosphere as a streak of light or shooting star,it is referred to as a _______________.

Why are there so many more impact craters visible on the Moon than on the Earth?

Venus resembles Earth in size,density,and distance from the Sun,but has a dense cloud cover of CO_2. Its air temperature is _________ that on Earth.