Question 1

Which of the following properties of the planets in our solar system is not explained by condensation theory?
A) direction of revolution
B) rotation rates
C) chemical compositions
D) orbital shapes

Accepted Answer

Condensation theory explains the direction of revolution, chemical compositions, and orbital shapes of planets but does not adequately explain the wide variation in rotation rates among the planets.

Question 2

Chunks of rock and metal that orbit the Sun but are much smaller than the planets are referred to as
A) comets
B) dwarf planets
C) meteors
D) asteroids

Accepted Answer

The term "chunks of rock and metal that orbit the Sun but are much smaller than the planets" describes asteroids. Comets are made up of ice and dust, and dwarf planets are larger than asteroids but not as big as regular planets. Meteors are asteroids that have entered Earth's atmosphere and are burning up.

Question 3

An alternative to the nebular theory for the formation of the solar system suggests that the planets formed from blobs of gas that had been gravitationally pulled out of the Sun during the near-collision with another star. This idea is referred to as the
A) fragmentation hypothesis
B) collision-ejection hypothesis
C) encounter hypothesis
D) tidal distortion hypothesis

Accepted Answer

The encounter hypothesis suggests that planets formed from material pulled out of the Sun during a close encounter with another star.

Question 4

The most abundant materials in the solar nebula were
A) hydrogen compounds like water, methane, and ammonia
B) hydrogen and helium gases
C) metals
D) rocks

Accepted Answer

The solar nebula was primarily composed of hydrogen and helium gases, making up about 99% of its mass. The remaining 1% was made up of heavier elements, including rocks and metals, as well as hydrogen compounds like water, methane, and ammonia. However, the most abundant material by far was hydrogen and helium gases.

Question 5

Assuming the encounter hypothesis is correct and planets can only form from the gravitational interactions between passing stars, what implications does this have for the possibility of life elsewhere in the universe?
A) there would be no possibility of life at all because close stellar encounters never occur
B) life would be exceedingly rare because close stellar encounters are exceedingly rare
C) we have no way to determine the probability of close stellar encounters so we have no way of knowing
D) life would be very common because stellar close encounters are constantly occurring

Accepted Answer

If planets can only form from the gravitational interactions between passing stars, then the formation of planetary systems would be rare because close stellar encounters are rare. This, in turn, would make the emergence of life rare. However, it should be noted that this is just one hypothesis and there are other ways in which planets and life could arise that do not depend on close stellar encounters.

Question 6

Compared to Jupiter and Saturn, Uranus and Neptune
A) are substantially larger
B) contain a much higher proportion of hydrogen compounds
C) have no ring systems
D) are much more massive

Accepted Answer

Uranus and Neptune contain a higher proportion of hydrogen compounds, such as water, methane, and ammonia, compared to Jupiter and Saturn which are predominantly composed of hydrogen and helium.

Question 7

Planetary rings are found around
A) all of the planets
B) the planet Saturn only
C) all of the Jovian planets
D) all of the terrestrial planets

Accepted Answer

Planetary rings are found around all of the Jovian planets, which include Jupiter, Saturn, Uranus, and Neptune. These gas giants have complex ring systems made up of dust, rock, and ice particles.

Question 8

Pluto, Eris and Ceres are all examples of
A) Kuiper belt objects
B) dwarf planets
C) asteroids
D) planets

Accepted Answer

Pluto, Eris and Ceres are all classified as dwarf planets, a term that was created by the International Astronomical Union in 2006 to describe objects in our solar system that are too small to be considered full-fledged planets.

Question 9

The outer Jovian planets most likely formed from
A) clumps of hydrogen and helium gas spun from a rapidly rotating protosun
B) larger collections of hydrogen and helium gas attracting particles of rock and ice to them
C) the collision and coalescence of clumps of hydrogen and helium gas within the solar nebula
D) planetesimals of rock and ice attracting hydrogen and helium gas from the solar nebula

Accepted Answer

The outer Jovian planets are believed to have formed from planetesimals of rock and ice that were able to attract hydrogen and helium gas from the solar nebula due to their significant mass. This process allowed them to grow into the gas giants we observe today.

Question 10

According to the nebular theory for the formation of the solar system,
A) planets should be rotating in the same direction as they orbit the Sun
B) planets can be rotating in any random direction compared to the direction they orbit the Sun
C) planets should be rotating in the opposite direction to the direction they orbit the Sun
D) no prediction is made as to the directions of rotations of the planets

Accepted Answer

According to the nebular theory for the formation of the solar system, planets should be rotating in the same direction as they orbit the Sun. This is because the planets were formed from the same rotating cloud of gas and dust which was also orbiting the Sun in a particular direction. Conservation of angular momentum ensured that the rotating cloud flattened into a disk shape with all the orbits and rotations in the same direction.

Question 11

The nebular theory predicts that
A) most stars should have planetary systems
B) only solar-type stars should have planetary systems
C) planetary systems are relatively rare
D) the Sun is unique in having a planetary system

Accepted Answer

The nebular theory predicts that most stars will have planetary systems because planets are formed from the same material as the star and are believed to form in the protoplanetary disk around the star during its formation.

Question 12

Which of the following materials present in the solar system had the highest condensation temperatures?
A) metals
B) rocks
C) hydrogen and helium gases
D) hydrogen compounds like water, methane, and ammonia

Accepted Answer

Metals have the highest condensation temperatures of all materials present in the solar system. This means that they are the first to solidify and condense out of the gas and dust present in the early solar system, forming the cores of planets and other rocky bodies. Rocks and hydrogen compounds like water, methane, and ammonia have lower condensation temperatures, while hydrogen and helium gases have the lowest condensation temperatures and remain as gas in most solar system environments.

Question 13

One of the unusual features of the Earth's moon is that it is
A) very large
B) very small
C) made mostly of rock
D) keeps one side facing the Earth

Accepted Answer

The Earth's moon is unusually large relative to the size of the planet it orbits, which is not common for moons in our solar system.

Question 14

Most of the extrasolar planetary systems discovered to date are
A) very similar to our own solar system with inner rocky terrestrial planets and outer gaseous Jovian planets
B) similar to our solar system in having inner rocky terrestrial planets but different in having no Jovian planets
C) identical to our own with the same number and types of planets as our own solar system
D) quite different than our own solar system, many with Jovian planets found close to their parent stars

Accepted Answer

Most of the extrasolar planetary systems discovered are quite different from our own solar system, with many having Jovian planets found close to their parent stars. This is very different from our own solar system, where the Jovian planets are located in the outer regions.

Question 15

According to the nebular theory, as an interstellar cloud forms a new star and planetary system it
A) expands, cools down, and spins slower
B) contracts, heats up, and spins faster
C) expands, cools down, and spins faster
D) contracts, heats up, and spins slower

Accepted Answer

According to the nebular theory, as an interstellar cloud collapses under its own gravity, it begins to contract, which causes an increase in temperature and density. This heating causes the cloud to start rotating faster due to conservation of angular momentum. As the cloud continues to contract and spin faster, it flattens into a disk-shaped structure with a central protostar and surrounding protoplanetary disk. Thus, the correct answer is B - the cloud contracts, heats up, and spins faster.

Question 16

In the outer regions of the solar nebula where temperatures were low,
A) only rock and iron could condense
B) only hydrogen compounds could condense as ices
C) hydrogen and helium gases were able to condense
D) in addition to rock and iron, hydrogen compounds also condensed as ices

Accepted Answer

In the outer regions of the solar nebula where temperatures were low, not only rock and iron but also hydrogen compounds such as water, methane, and ammonia could condense as ices. This is why the outer planets of our solar system are primarily composed of rock and ice.

Question 17

The process of planet formation in the early solar system is best described by which of the following terms?
A) precipitation
B) consolidation
C) condensation
D) crystallization

Accepted Answer

The process of planet formation in the early solar system involves the condensation of solid particles from the gas and dust of the solar nebula, which then accrete to form larger and larger bodies. Precipitation, consolidation, and crystallization are not accurate descriptions of this process.

Question 18

Apart from terrestrial planets, another promising place to find life in the solar system is
A) inside comets
B) beneath the surfaces of icy Jovian moons
C) in the atmospheres of Jovian planets
D) inside asteroids

Accepted Answer

Beneath the surfaces of icy Jovian moons, such as Europa, Ganymede, and Enceladus, there may be subsurface oceans of liquid water, which could potentially support life. These moons have also been found to have organic molecules and geological activity that could provide energy sources for life. The other options do not have as much research or evidence to support the possibility of life.

Question 19

Far from the Sun in a spherical cloud surrounding the solar system we find
A) Orion's belt
B) the Oort cloud
C) the asteroid belt
D) the Kuiper cloud

Accepted Answer

The Oort cloud is a spherical cloud that surrounds the solar system and is located far from the Sun. The other options, Orion's belt, the asteroid belt, and the Kuiper cloud, are not located in a spherical cloud surrounding the solar system.

Question 20

Given the basic building blocks of planets are widespread and the same laws of physics operate everywhere, we would expect
A) we have not detected any other planetary systems so we have no way of knowing
B) other planetary systems to be identical to our own with the same number and types of planets as our own solar system
C) other planetary systems to be laid out in a similar manner to our own with inner rocky terrestrial planets and outer gaseous Jovian planets
D) other planetary systems to be very different than our own because the detailed conditions that existed in our own solar nebula are unlikely to have been replicated elsewhere

Accepted Answer

The fact that basic building blocks of planets are widespread and the same laws of physics operate everywhere suggests that other planetary systems would also consist of inner rocky terrestrial planets and outer gaseous Jovian planets, similar to our own solar system. The formation of planets is largely determined by the conditions within the solar nebula, and these conditions are expected to be fairly common in other star-forming regions. While there may be some variations in the composition or number of planets, the basic layout of other planetary systems is likely to be similar to our own. Option A is incorrect because we have detected other planetary systems, and they provide evidence that supports this idea. Option B is incorrect because the number and types of planets can vary based on a variety of factors. Option D is incorrect because while there may be some differences in the details, the overall structure of other planetary systems is expected to be similar to our own.

Quiz 3: The Universal Context of Life

Which of the following properties of the planets in our solar system is not explained by condensation theory?

Chunks of rock and metal that orbit the Sun but are much smaller than the planets are referred to as

An alternative to the nebular theory for the formation of the solar system suggests that the planets formed from blobs of gas that had been gravitationally pulled out of the Sun during the near-collision with another star. This idea is referred to as the

The most abundant materials in the solar nebula were

Assuming the encounter hypothesis is correct and planets can only form from the gravitational interactions between passing stars, what implications does this have for the possibility of life elsewhere in the universe?

Compared to Jupiter and Saturn, Uranus and Neptune

Planetary rings are found around

Pluto, Eris and Ceres are all examples of

The outer Jovian planets most likely formed from

According to the nebular theory for the formation of the solar system,

The nebular theory predicts that

Which of the following materials present in the solar system had the highest condensation temperatures?

One of the unusual features of the Earth's moon is that it is

Most of the extrasolar planetary systems discovered to date are

According to the nebular theory, as an interstellar cloud forms a new star and planetary system it

In the outer regions of the solar nebula where temperatures were low,

The process of planet formation in the early solar system is best described by which of the following terms?

Apart from terrestrial planets, another promising place to find life in the solar system is

Far from the Sun in a spherical cloud surrounding the solar system we find

Given the basic building blocks of planets are widespread and the same laws of physics operate everywhere, we would expect