Deck 4: Exploring Our Evolving Solar System

Question 1

The conservation of angular momentum predicts that,when an object collapses,it spins slower.

Answer 1

False

Question 2

A T Tauri wind only occurs in very old and stable stars.

Answer 2

False

Question 3

Exosolar planets are thought to be planets that are orbiting our Sun that have not yet been discovered.

Answer 3

False

Question 4

The chemical composition of the planets is determined by the measure of their radial velocity through the Doppler effect.

Question 5

The outer planets have thick,gaseous atmospheres rich in hydrogen,helium,and methane.

Question 6

Planets form from the material in a protoplanetary disk.

Question 7

Asteroids were likely never part of a planet-sized body.

Question 8

Chemical differentiation is when heavy materials sink to the core of a planet and the lighter materials rise to the surface.

Question 9

Planets are formed first as planetesimals and then as protoplanets.

Question 10

Several large satellites of the Jovian planets are almost as big as the inner,terrestrial planets.

Question 11

Very few extrasolar planets have been discovered.

Question 12

Terrestrial planets have rocky cores and few moons,if any.

Question 13

It is likely to find frozen methane on the terrestrial planets.

Question 14

The largest of the trans-Neptunian objects (TNOs)are called dwarf planets.

Question 15

Extrasolar planets have not yet been imaged directly.

Question 16

The Oort cloud is comprised of a swarm of potential comets.

Question 17

Jovian planets have volcanic features on their surfaces.

Question 18

In increasing distance from the Sun,the correct listing of collections of objects is the asteroid belt,the Oort cloud,and then the Kuiper belt.

Question 19

In differentiation,iron-rich materials float to the surface of a planet and the silicon-rich materials sink to the center.

Question 20

The Sun and planets formed from a rotating solar nebula.

Question 21

Earth has an average density of 5500 kg/m³,whereas the density of rock on its surface is about 3000 kg/m³.What conclusion can be reached about Earth's core from this observation?

A) The core is composed of material with density about twice that of the surface material.
B) The core consists of lower density material than surface rock.
C) The core is very hot.
D) The core is made of material far denser than surface rock.

Question 22

The main characteristics of our solar system are

A) two large planets close to the Sun,two small planets next out,and four large planets farthest from the Sun.
B) two small planets close to the Sun,five larger planets much farther from the Sun,and one small planet very far from the Sun.
C) four small planets close to the Sun and four large planets far from the Sun.
D) three small planets close to the Sun and five large planets far from the Sun.

Question 23

Which of the following general statements about all of the planets in the planetary system is true?

A) They have hard,rocky surfaces,which can be seen and photographed.
B) They orbit the Sun in the same direction.
C) They have satellites or moons.
D) They have very dense atmospheres.

Question 24

The smallest of the planets is

A) Neptune.
B) Mars.
C) Mercury.
D) Venus.

Question 25

The planet whose average density is less than that of water is

A) Jupiter.
B) Neptune.
C) Saturn.
D) Earth.

Question 26

The overall shape of the orbits of most of the planets in the solar system is

A) slightly elliptical but nearly circular.
B) parabolic.
C) perfectly circular.
D) elliptical,very elongated.

Question 27

The average number of natural satellites (moons)per planet for the terrestrial planets is

A) less than one.
B) exactly one.
C) at least eight.
D) just over two.

Question 28

A curious fact about the structure of the planet Jupiter,compared with that of Earth,is that it has

A) much greater mass but much lower average density.
B) about the same mass but much greater density.
C) much greater mass and greater average density.
D) much greater mass but about the same density.

Question 29

Which planets do NOT have natural satellites (moons)?

A) Jupiter and Uranus
B) Uranus and Mars
C) Mars and Venus
D) Venus and Mercury

Question 30

The mean density of a planet is

A) another way of describing its total mass.
B) the amount of mass in one cubic meter of material at the planet's surface.
C) the amount of mass in one cubic meter of material in the planet's core.
D) its total mass divided by its volume.

Question 31

Which of the following statements is TRUE?

A) Jupiter has the highest average density among the planets.
B) The average mass of terrestrial planets is close to the average mass of the Jovian planets.
C) Earth is the most massive of terrestrial planets.
D) Earth is the biggest planet.

Question 32

In our solar system,which of the following planets is NOT a member of the terrestrial group?

A) Mercury
B) Jupiter
C) Venus
D) Mars

Question 33

Which is the largest planet in our solar system?

A) Saturn
B) Earth
C) Uranus
D) Jupiter

Question 34

The mass of a planet is determined primarily by what method?

A) Measurement of its orbital eccentricity
B) Measurement of its diameter by photography
C) Observation of its gravitational influence on an orbiting moon
D) Measurement of its average temperature by remote sensing

Question 35

The correct sequence of planets in our solar system from the Sun outward is

A) Mercury,Venus,Earth,Mars,Saturn,Uranus,Jupiter,Neptune.
B) Mercury,Earth,Venus,Mars,Jupiter,Saturn,Uranus,Neptune.
C) Mercury,Venus,Mars,Earth,Jupiter,Saturn,Uranus,Neptune.
D) Mercury,Venus,Earth,Mars,Jupiter,Saturn,Uranus,Neptune.

Question 36

Orbital eccentricity is a number that describes the

A) rate of rotation of the semimajor axis of the orbit because of precession.
B) orbital tilt with respect to the plane of Earth's orbit,in degrees.
C) mean diameter of the orbit.
D) shape of the orbital ellipse.

Question 37

Suppose that observers using the Hubble Space Telescope detect,around several solar-type stars,the presence of planets with the following characteristics: low density;large size;polar diameters shorter than equatorial diameters;fluid surfaces;and rapid rotation.How would these planets be classified in terms of our solar system?

A) Asteroids
B) Terrestrial planets
C) Comet nuclei
D) Jovian planets

Question 38

The planet whose orbit has the greatest eccentricity is

A) Mars.
B) Earth.
C) Mercury.
D) Uranus.

Question 39

Suppose that in 2008,observers using the Hubble Space Telescope discover a series of planets with the following characteristics moving around a star resembling our Sun: spherical;solid surfaces;mean densities about 4 times that of H₂O;radii about 4000 km;and low-density atmospheres.How would these planets be classified in terms of our solar system?

A) Jovian planets
B) Cometary nuclei
C) Asteroids
D) Terrestrial planets

Question 40

The average density of the massive Jovian planets is

A) much lower than the density of water because of the amount of hydrogen they contain.
B) much higher than the density of Earth rocks due to the great gravitational compression of their interiors.
C) close to the density of basaltic rocks on Earth.
D) close to the density of water.

Question 41

Pluto is now categorized as a(n)

A) dwarf planet.
B) comet.
C) planet.
D) asteroid.

Question 42

The largest known asteroid in our solar system is

A) Gaspra.
B) Titan.
C) Pallas.
D) Ceres.

Question 43

The asteroid belt exists between the orbits of which planets?

A) Mars and Jupiter
B) Earth and Mars
C) Jupiter and Saturn
D) Venus and Earth

Question 44

Determination of the chemical composition of the atmospheres of the planets is carried out most effectively by what type of study?

A) Photometry-the measurement of the fading of light from their moons as they pass behind the planet's atmosphere
B) Measurement of their relative mean densities
C) Measurement of their atmospheric temperature
D) Spectroscopy-the measurement of absorption features in their spectra

Question 45

The trans-Neptunian objects (such as Pluto,Sedna,Quaoar,etc. )are

A) asteroids in the outer part of the asteroid belt.
B) small planets that circle the Sun between the orbits of Neptune and Uranus.
C) small worlds of rock and ice,most of which orbit within the Kuiper belt.
D) asteroids captured as moons by the Jovian planets.

Question 46

The two largest trans-Neptunian objects are

A) Neptune and Uranus.
B) Pluto and Eris.
C) Sedna and Quaoar.
D) Ceres and Pallas.

Question 47

The birthplace of the Sun and planets (and of other stars and maybe their planets)is thought to have been

A) in cool gas and dust clouds.
B) at the centers of supernova explosions.
C) in the centers of galaxies.
D) in black holes dotted about the universe.

Question 48

Which one of the following bodies has the most elliptical orbit?

A) Earth
B) Mars
C) Mercury
D) Pluto

Question 49

The seven largest satellites in the solar system,in their size and physical characteristics,most resemble

A) the terrestrial planets.
B) the Jovian planets.
C) Mercury.
D) the asteroids.

Question 50

The idea that the Sun and planets formed from a large cloud of gas and dust was first proposed by

A) Edwin Hubble.
B) Aristotle.
C) Sir William Herschel.
D) Kant and Laplace.

Question 51

The most abundant elements in the universe are

A) hydrogen and helium.
B) oxygen and nitrogen.
C) iron and gold.
D) silicon and lithium.

Question 52

A ground-based telescope is pointed at the atmosphere of Titan and a spectrum is made.The spectral lines observed in this spectrum

A) can only be features of Titan.
B) can be characteristic of Earth's atmosphere as well as Titan's atmosphere.
C) can be characteristic of the cooler,outer layers of the Sun's atmosphere as well as of Titan's atmosphere.
D) can be characteristic of the atmospheres of Titan and Earth and also of the cooler,outer layers of the Sun's atmosphere.

Question 53

The Oort cloud is

A) a band of dust in the plane of the ecliptic,extending from the orbit of Mars beyond the orbit of Pluto.
B) an approximate spherical distribution of comets centered on the Sun,extending out to about 50,000 AU.
C) another name for the early solar nebula.
D) a relatively flat distribution of comets in the plane of the ecliptic,extending from around the orbit of Pluto out to about 500 AU from the Sun.

Question 54

The mean density of the trans-Neptunian object Pluto is most similar to the densities of the

A) terrestrial planets.
B) Jovian planets.
C) large moons of Jupiter and Saturn.
D) asteroids.

Question 55

An asteroid is

A) another name for the nucleus of a comet,a volatile object that moves around the Sun in a long,elliptical orbit.
B) an object smaller than a planet,moving around the Sun in an orbit close to the plane of the ecliptic.
C) a meteorite before it enters the atmosphere and plunges to Earth.
D) a small,easily recognizable group of stars within a constellation.

Question 56

Most comet nuclei are believed to be

A) chunks of rock or iron chipped from asteroids by impacts.
B) large carbon chondrite meteoroids that have been set on fire by the Sun and are trailing long smoke trails.
C) chunks of water and methane ice ejected from the surface of the icy satellites of the outer planets by asteroid impacts.
D) chunks of dirty ice left over from the formation of the solar system.

Question 57

Most of the elements beyond H and He in the periodic table in our Sun and solar system probably originated

A) in the original Big Bang.
B) from the center of our own Sun,through fusion and later ejection as solar wind.
C) from chemical reactions in planetary atmospheres.
D) from fusion reactions in the centers of earlier stars.

Question 58

The most likely origin of the "dirty snowballs" that become long-period comets when deflected into orbits bringing them closer to the Sun is the

A) Oort cloud surrounding the solar system.
B) surfaces of the moons of Jupiter and Saturn.
C) gas clouds in the Milky Way.
D) asteroid belt.

Question 59

The asteroid belt is believed by most astronomers to be composed of

A) icy fragments similar to the nuclei of comets.
B) genuine leather.
C) rocky debris left over from the formation of the solar system.
D) the remnants of a gaseous planet disrupted by an impact.

Question 60

The Kuiper belt is

A) a band of asteroids between the orbits of Jupiter and Saturn.
B) a group of icy objects that falls between Neptune and Uranus but orbits in the opposite direction.
C) a band of trans-Neptunian objects that lies within 30-50 AU from the Sun and is centered on the ecliptic.
D) the largest cloud band in Jupiter's atmosphere.

Question 61

The three common substances believed to have been important in planet formation are

A) water,carbon dioxide ice (dry ice),and iron.
B) solid,liquid,and gaseous hydrogen.
C) hydrogen,helium,and neon gases.
D) rocks,ices,and gas.

Question 62

The manner in which the terrestrial planets formed was

A) accretion of planetesimals to form a core,followed by gravitational capture of gas from the solar nebula.
B) gravitational condensation of hydrogen,helium,and dust in eddies or vortices in the solar nebula.
C) gravitational condensation of gas followed by capture of solid planetesimals.
D) accretion of solid planetesimals containing mostly rocky material.

Question 63

The temperature began to rise at the center of the solar nebula because

A) the nebula was contracting and that fast-moving material collided and increased the thermal energy.
B) supernova explosions were stirring up the material there and causing turbulence.
C) fusion reactions were beginning in the core,releasing tremendous amounts of heat.
D) massive stars nearby were heating the nebula with their ultraviolet radiation.

Question 64

The material from which our solar system formed is believed to be

A) the hot,dense gases at the center of a globular star cluster.
B) a vast cloud of pure hydrogen.
C) the convergence of the solar winds of several nearby stars.
D) a cold,dark cloud of gas and dust.

Question 65

Suppose you were to go back in time and explore the early solar nebula (during the formation of the solar system).If you were to travel outward from the protosun,the first solid material you would encounter would be

A) dust-sized grains of iron and rocky material.
B) dust-sized grains of frozen hydrogen,water,ice,and rocky minerals.
C) snowflakes made of frozen water,methane,ammonia,and carbon dioxide.
D) snowflakes of frozen hydrogen and helium.

Question 66

A proplyd is

A) a primitive organism thought to exist on Jupiter's moon,Europa.
B) a protoplanetary disk,such as is observed around some stars in the Orion nebula,for example.
C) any planet of greater mass than Jupiter.
D) a planet orbiting a star beyond the Sun.

Question 67

The process of accretion in planetary formation is the

A) slow accumulation of solid particles by gravity and collision into larger,solid objects.
B) slow acquisition from deep space by the giant planets of their complement of moons,by gravitational capture.
C) slow condensation by gravity of gas atoms into large dense gas clouds,which become the planets.
D) relatively rapid gravitational collapse (in less than 10⁶ years)of gas clouds to form planets.

Question 68

More than any other,which physical parameter probably controlled the early evolution of the planetary system and dictated the characteristics of the planets that eventually formed?

A) Overall rotation of the nebula
B) Density of hydrogen gas in the nebula
C) Mix of chemical constituents
D) Temperature distribution within the nebula

Question 69

The most probable theory for the solar system's formation is

A) a capture theory in which the Sun captured objects moving through space,which then became the planets.
B) an encounter in which a passing star ripped off material from the Sun to form the planets.
C) gas and dust clouds condensed to form the Sun,whereas planets formed later within a nebular disk.
D) condensation of a slowly contracting nebula of hot gas,first into planets in the outer region,then into the Sun at the center.

Question 70

If a large cloud of gas and dust is initially rotating,and it begins to contract without losing any mass,it will rotate

A) faster.
B) more slowly.
C) at a constant rate.
D) at a rate that initially decreases and then increases as the disk shape is achieved.

Question 71

The reason for the vast amount of hydrogen in the interior of Jupiter is probably that

A) Jupiter formed from mutual gravitational contraction of the primordial hydrogen gas.
B) the mass of the initial condensation of rocks at Jupiter's orbit was sufficient to attract vast amounts of gas to it.
C) nuclear fission of atoms in Jupiter's interior split all nuclei down to hydrogen nuclei early in its history.
D) Jupiter became so hot in its interior that all kinds of atoms and molecules were melted down and dissociated into the fundamental atom-hydrogen.

Question 72

The most probable time sequence for the solar system's formation was that the

A) Sun formed initially,and the planets and major moons were captured much later as they drifted by the Sun.
B) planets formed first out of the cold gas and dust nebula,followed by the Sun,which formed when the gas had become much hotter.
C) Sun formed first,the planets were spun off from the Sun,and the moons in turn were spun off from the planets.
D) Sun contracted first as a ball of gas,and the planets and moons formed shortly afterward by accretion and condensation.

Question 73

What name is given to the concentration of mass that formed at the center of the solar nebula,eventually becoming the Sun?

A) Antisun
B) Protosun
C) Nebular core
D) Pseudosun

Question 74

In order for the disk instability model to be able to account for the formation of the Jovian planets,

A) the rocky material would have to be confined completely to the inner part of the solar system.
B) the gas in the nebular disk would have to be at a very high temperature.
C) the gas in the nebular disk would have to be clumpy rather than smooth.
D) the gas in the nebular disk would have to be mostly methane and ammonia rather than hydrogen and helium.

Question 75

The early phases of planetary formation into protoplanets were characterized by

A) slow accretion of small particles by gravitational attraction and collision.
B) condensation of hot gas clouds.
C) the shattering collision of very large objects into planet-sized fragments.
D) violent collapse and heating of gas and dust grains by gravity.

Question 76

What was the form of the material from which the solar system formed?

A) A nebula made mostly of hydrogen and helium gas,but enriched in heavier elements from supernova explosions
B) A nebula made mostly of heavy elements,but enriched in hydrogen and helium from the supernova explosions
C) A nebula made entirely of hydrogen and helium gas
D) Debris from the explosion of a massive star

Question 77

The most probable process for the formation or acquisition of the Sun's planets is

A) the breakup of one single large companion body to the Sun,by tidal distortion.
B) the freezing of immense gas clouds by the cold temperature of space.
C) capture of planets from outer space by gravity.
D) relatively slow growth of smaller objects by collisions and mutual gravitational attraction.

Question 78

A T Tauri wind is

A) the rapid condensation of gas onto a Jovian-type protoplanet.
B) a slow expulsion of the outer layers of a solar-type star,extending over a large part of its life.
C) a wind created by the orbital motion of protoplanets through a young solar-type nebula.
D) a rapid expulsion of the tenuous outer layers of a young star.

Question 79

In describing the early solar system,we discuss solids and vapors but no liquids.Why do we believe liquids were absent?

A) The solar system was too cold to permit liquids to exist.
B) The solar system was too warm to permit liquids to exist.
C) The pressure in the solar nebula was too low to permit liquids to exist.
D) The pressure in the solar nebula was too high to permit liquids to exist.

Question 80

Which one of the following is NOT an example of the conservation of angular momentum?

A) A figure skater spins faster as she brings her arms in close to her body.
B) Earth moves faster in its orbit at those times of the year when it is closer to the Sun (Kepler's second law).
C) The particles in the nebula around a protostar move faster in their orbits as the nebula collapses inward.
D) The Moon always keeps one face pointed toward Earth.