Mastering Astronomy Final - Unit 2

A few of the characteristics that a model of solar system formation must explain are illustrated in the figure below; choose which one(s) apply to this figure.

- A collection of asteroid-sized objects orbits beyond Neptune in the Kuiper belt. - Planets orbit with nearly circular orbits. - Planets are comparatively isolated in space.

To be effective, a scientific theory must be continually tested. If observations and experiments favor it, a theory can be further developed and refined. If they do not, the theory must be reformulated or rejected. Comparing what you know about the predictions of each Moon formation theory, determine which of the following observations and experiments have been verified.

- Earth has a large iron core; the Moon does not. - The mantles of Earth and the Moon have similar compositions. - Computer simulations predict that a collision between Earth and a Mars-sized object would produce a Moon-sized satellite with a stable orbit.

Below are two additional figures (Figure A and Figure B) that illustrate characteristics of the solar system.

- Figure B: Planetary properties of the solar system are highly differentiated. - Figure A: Primitive comets in the Oort cloud orbit the Sun with inclined orbits and reside at a great distance from the Sun.

Part B Since the early 1990s, observations of the solar system beyond Neptune, where Pluto resides, have revealed numerous objects orbiting the Sun. This collection of objects is known as the Kuiper belt. More Kuiper belt objects are being discovered each year, providing astronomers with a better understanding of their physical and orbital properties. From the list below, identify which properties are characteristic of Kuiper belt objects. Select all that apply:

- Kuiper belt objects orbit the Sun at great distances. - Kuiper belt objects have a low relative brightness when observed from Earth - Kuiper belt objects are small, icy bodies. - About 25% of Kuiper belt objects have the same orbital period as Pluto.

Consider the figure below and determine which characteristics of the solar system it illustrates.

- Planets orbit in the same direction as the Sun rotates on its axis. - Mostly satellite orbital direction is the same as the satellites' parent planet rotational direction. - Mostly the direction of planetary rotation is the same as the direction of the Sun's rotation.

Part C As astronomers continued to study Pluto and objects in the Kuiper belt, it became clear that Pluto has more in common with Kuiper belt objects than with the eight major planets in the solar system. With the discovery of Eris, an object even larger than Pluto, the International Astronomical Union introduced a new category of solar system objects called dwarf planets. Pluto was reclassified as a dwarf planet in 2006. Which of the following factors contributed to the evolution of scientific thinking that led to the reclassification of Pluto as a dwarf planet? Select all that apply:

- Terminology and classifications changed as scientific understanding and knowledge evolved. - More precise observations provided new information about the nature of Pluto. - Better technology led to improved understanding of objects in the solar system.

It is thought that Mars used to have running water on the surface. Which of the following are necessary consequences of that idea?

- The atmosphere used to be thicker. - The temperature used to be warmer.

Which of the following are found on the surface of Mercury?

- craters - scarps

All four jovian planets have storm systems in their atmospheres. From the list below, select the atmospheric characteristics that are found on all four jovian planets. Select all that apply.

- rapid winds - small oval-shaped storm systems - banded atmospheric patterns consisting of light colored zones

Match the words in the left-hand column to the appropriate blank in the sentences in the right-hand column. Use each word only once.

1. About a trillion comets are thought to be located far, far beyond Pluto in the OORT CLOUD. 2. The bright spherical part of a comet observed when it is close to the Sun is the COMA. 3. A comet's PLASMA TAIL stretches directly away from the Sun. 4. A comet's NUCLEUS the frozen portion of a comet. 5. Particles ejected from a comet can cause a(n) METEOR SHOWER on Earth. 6. The KUIPER BELT extends from about beyond the orbit of Neptune to about twice the distance of Neptune from the Sun.

Before you can determine which theory best fits the data, you need to define the three theories. Drag the theories on the left to the appropriate blanks on the right to complete the sentences. Make certain each sentence is complete before submitting your answer.

1. According to the COFORMATION (OR SISTER) theory, Earth and the Moon formed at about the same time out of the same pre-planetary matter. 2. The CAPTURE THEORY states that the Moon formed far from Earth and later became gravitationally bound by Earth after a close encounter. 3. A glancing collision between a large, Mars-sized object and a youthful, molten Earth led to formation of the Moon according to the IMPACT THEORY.

Jupiter's moon Europa might harbor life because it has which of the following conditions?

A liquid water subsurface layer

When did most of the cratering on the Moon occur?

About 4 billion years ago

Meteorites are important because

All of the above are true.

According to Figure 7.9 (Jupiter's Atmosphere) in the textbook, if ammonia and ammonium hydrosulfide ice were transparent to visible light, Jupiter would appear

Bluish

What is the primary cause of the aurorae (Northern and Southern lights)?

Charged particles interacting with the atmosphere

Listed following are several objects in the solar system. Rank these objects from left to right based on their distance from the Sun, from closest to farthest.

Closest to farthest: - a typical asteroid in the asteroid belt - a typical Kuiper belt object - a typical Oort Cloud object

Part complete The following images show Earth and the four jovian planets of our solar system. Rank these planets from left to right based on their distance from the Sun, from closest to farthest. (Not to scale.)

Closest to farthest: - earth - Jupiter - saturn - uranus - neptune

A theory is a framework of ideas and assumptions used to explain some set of observations and to make predictions about the real world. Each of the three theories for the formation of the Moon lead to different predictions about evidence that we should find. Which of the following predictions should be true if each theory is correct? Drag each prediction to the appropriate bin. If a prediction follows from more than one theory, place it in the "multiple theories" bin.

Coformation theory: - The Moon and Earth should have very similar compositions. Capture theory - The Moon and Earth should have completely different compositions. - Mathematical models would need to predict that the capture of a Moon-sized satellite would be likely in Earth's early history. Impact theory - The Moon and Earth should have similar mantle compositions, but other parts of their compositions should be dissimilar. - Computer simulations would need to predict that a collision between Earth and a Mars-sized object would produce a Moon-sized satellite with a stable orbit Multiple theories NONE

What is the source of the material of a meteor shower?

Comets

Part complete What phenomenon causes all weather and wind on Earth?

Convection

What caused the scarps found on Mercury?

Cooling of the planet and shrinking of the crust

Based on the evidence for the impact theory, what was the most probable order of events for the collision that led to the formation of the Moon? Rank the steps of the impact theory from earliest to latest. If two steps occurred at precisely the same moment, place one on top of the other.

Earlest to latest: - iron core of earth forms - mars-sized object collides with earth - if the mars-sized object has an iron core, most or all it is left behind on Earth and merges with Earth's core - the moon forms out of rocky debris ejected from Earth during the collision

Earth's magnetic field is the result of our planet's large, permanently magnetized iron core

False

Like Earth, the Moon has a molten metal core.

False

Part A: The following images show four types (wavelengths) of light. Rank these from left to right based on the amount of each that is emitted (as thermal radiation) by Earth's surface, from greatest to least. If you think that two (or more) types should be ranked as equal, drag one on top of the other(s) to show this equality.

Greatest amount: infrared Least amount: - visible -ultraviolet - x-ray

Part B: In Part A, you found that Earth emits only infrared light. This infrared light can be absorbed by greenhouse gases, such as carbon dioxide and water vapor, in the atmosphere. In fact, all the terrestrial planets emit infrared light from their surfaces. The following images show the four terrestrial planets in our solar system. Rank these planets from left to right based on the total amount of infrared-absorbing greenhouse gases in their atmospheres, from greatest to least.

Greatest greenhouse gas abundance to least: Greatest: -venus -earth -mars -mercury

The Moon and Earth interact through their mutual gravitational forces. The Moon's rotation rate and the ocean tides on Earth are consequences of the gravitational tidal forces exerted by each body on the other. Considering the Moon, rank the gravitational tidal force exerted on it by Earth for three

Greatest: near side (A) Middle: Midway (B) Least: farside (C)

The medium-sized Jovian moons are mostly made of what materials?

Ice and rock

What is the source of Mars's red color?

Iron oxide in the soil

It is important to observe the concentration of carbon dioxide in the atmosphere because:

It is an important Greenhouse gas, and its increased concentration can warm the planet.

When is Mercury visible in the night sky?

It is seen at most for 2 hours, just before sunrise and just after sunset.

Evidence that Triton probably did not form around Neptune is

It orbits around Neptune in retrograde (backwards), opposite to the rotation of Neptune.

In appearance, what immediately distinguishes Saturn from all the other planets?

Its large ring system

Which of the following statements is NOT true about Saturn's moon Titan?

Its surface temperature is about the same as that of Earth.

Astronomers have detected storms in the atmospheres of the jovian planets, including giant storms that are larger than the entire planet Earth. Listed below are characteristics of storms. Sort these characteristics according to whether they are associated with jovian storms only, terrestrial storms only, or both jovian and terrestrial storms. Drag the appropriate items to their respective bins.

Jovian storms only: - Associated with oppositely-directed high-speed atmospheric flows - Hosted by rapidly-rotating planet Terrestrial storms only - Powered by solar radiation - Short-lived (hours to days)

The most massive planet in the solar system is

Jupiter

The low densities of the Jovian planets tell us they are mostly composed of what materials?

Light gases

The farthest major planet from the Sun is

Neptune

What was the first planet discovered by mathematical prediction?

Neptune

Which of the following Mars surface features provides dramatic evidence that volcanism has played a role in shaping the surface of Mars?

Olympus Mons

Which of the following is NOT true about the relationship between Mercury's orbit and spin?

One side of Mercury always faces the Sun

Consider the figure below and determine which property or properties of the solar system it illustrates.

Planets orbit in virtually the same plane.

Part A Pluto was first observed in 1930, and its largest moon, Charon, was discovered in 1978. A few years after Charon's discovery, astronomers were able to observe a series of eclipses as Pluto and Charon passed in front of one another. By studying how the brightness of Pluto and Charon changed as they eclipsed each other, astronomers were able to measure the masses and radii of both Pluto and its moon. What did these measurements imply about the average densities of Pluto and Charon?

Pluto and Charon have average densities that are expected for objects made mostly of water ice.

The most widely accepted theory of solar system formation is the condensation theory, which states that the solar system formed some 4.6 billion years ago from the solar nebula, a cloud fragment of the Milky Way's interstellar medium. The slow rotation of the solar nebula allowed for a disk of material to develop. Protoplanets began to form in the disk and use up surrounding material. The heat from the Sun prevented light elements from forming in the inner solar system, which left behind an abundance of heavy elements that would eventually form the inner planets. Any leftover debris was cleared out of the solar system, some of which became the comets in the Oort cloud. Eventually, after roughly 100 million years, the solar system was formed. The condensation theory explains the solar system's properties listed in Parts A through D of this tutorial. Match each of the given properties of our solar system with the corresponding aspect of the condensation theory that explains it. (Note that multiple properties may correspond to the same aspect of the condensation theory).

Smaller bodies, such as moons and planets, inherit the rotation of the object they orbit: - The direction of planetary rotation is the same as the direction of the Sun's rotation. - Satellite orbital direction is the same as its parent planet orbital direction. Solar radiation heats up the solar nebula and prevents light elements from forming in the inner solar system: - Planetary properties of the solar system are highly differentiated. Forming protoplanets begin to accrete, or sweep up, surrounding debris: -Planets are comparatively isolated in space. The solar nebula has a disk-like shape and rotates in a single plane: - Planets orbit with nearly circular orbits. - Planets orbit in virtually the same plane. - Planets orbit in the same direction as the Sun rotates on its axis Asteroids and comets originated from leftover debris from the accretion-fragmentation stage: - Asteroids are very old and do not possess the characteristics of the terrestrial or jovian planets. - A collection of asteroid-sized objects orbits beyond Neptune in the Kuiper belt. - Primitive comets in the Oort cloud orbit the Sun with inclined orbits and reside at great distances from the Sun.

What is the cause of the colors of Io's surface?

Sulfur compounds

Assuming that features you see on Mars are similar to features found on Earth, what would a casual inspection of the interactive photo of Mars lead you to suspect about water on Mars?

Surface water only exists as frozen ice.

Which of the following is NOT a property of our solar system we must account for in a theory of its origin?

The Earth is the only planet that is known to have life.

Which of the following is true?

The deeper you dive into the atmospheres of the outer planets, the higher the temperature.

Which of the following statements about global warming is NOT true?

The global mean temperature in the modern era is the highest is has ever been.

Which of the following is NOT a way in which the terrestrial and jovian planets differ?

The jovian planets have orbits that are highly inclined to the ecliptic and do not revolve in the same direction as the terrestrial planets.

How does the age of the lunar highlands compare to the age of the lunar maria?

The maria are a few hundred million years younger.

Which of the following is the best description of our knowledge of the surface of Venus?

The surface is extremely dry, with evidence of past volcanic events.

Why do asteroids look like "dots" to Earth-based telescopes?

They are very small.

Which statement best describes the shield volcanoes on Venus?

They are wider than they are tall.

What makes Titan unique among the moons of the solar system?

Thick, cloudy atmosphere

The only moon with a thick atmosphere is

Titan

Mercury's solar day is longer than its solar year

True

Motion of the crustal plates is driven by convection in Earth's upper mantle.

True

Uranus has no large moons.

True

Which of the planets below has the greatest tilt of its rotation axis?

Uranus

Which terrestrial planet would have its surface temperature the most dramatically changed if its greenhouse gases were removed from its atmosphere?

Venus

Listed below are geographic features of the terrestrial worlds. In each case, identify the geological process: impact cratering, volcanism, erosion, or tectonics (where tectonics is any large-scale processes affecting the structure of the planetary crust), most responsible for the feature described. Match the geographic feature to the appropriate geologic process.

Volcanism: - big island of Hawaii - smooth surfaces of the lunar Maria - mar's Olympus mons Impact cratering: - old surface features of the lunar highlands Erosion: - earth's Grand Canyon

Increasing the concentration of greenhouse gases in Earth's atmosphere

decreases the transparency of the atmosphere to infrared light.

The ingredients of a typical comet's nucleus are most likely ________.

dust and rocky particles trapped in methane, ammonia, and water ice

When you zoom in on the section labeled "Southern Highlands," which geologic processes are most clearly evident?

impact cratering and erosion

The first figure in Discovery 5-2 shows that CO2 levels in Earth's atmosphere began to rise rapidly

in the mid-19th century

Part complete The following images show Earth and the four jovian planets of our solar system. Rank these planets from left to right based on their mass, from lowest to highest. (Not to scale.)

lowest mass to largest mass: - earth - uranus - neptune - saturn - Jupiter

Listed following are several objects in the solar system. Rank these objects from left to right based on the distance from the Sun at which they are presumed to have formed, from nearest to farthest.

nearest to farthest: - a typical asteroid in the asteroid belt - a typical oort could object - a typical Kuiper belt object

Compared with Uranus, the planet Neptune is

roughly the same size

What is currently the best way to study the interior structure of the Earth?

seismic waves from earthquakes

Listed following are several objects in the solar system. Rank these objects from left to right based on their orbital period around the Sun from shortest to longest.

shortest to longest: - a typical asteroid int eh asteroid belt - a typical Kuiper belt object - a typical Oort Cloud object

The following images show Earth and the four jovian planets of our solar system. Rank these planets from left to right based on their size (average equatorial radius), from smallest to largest. (Not to scale.)

smallest radius to largest radius: - earth - neptune - uranus - saturn - Jupiter

Generally, you would expect that the closer a moon is to a large planet,

the warmer its interior