Deck 8: Origins of the Solar System and Extrasolar Planets

Question 1

The hydrogen in our solar system was created from subatomic particles in ______.

A) the Earth
B) our sun
C) Jupiter
D) the Big Bang
E) supernovas

Answer 1

the Big Bang

Question 2

After the first solid grains formed in our solar system, these particles could then grow by the process of ____, the collision and sticking of one particle with another to continue the formation of planetesimals. Each of these has many atoms or molecules.

A) Accretion
B) Sublimation
C) Hydration
D) Condensation
E) Vaporization

Answer 2

Accretion

Question 3

____ is the separation of material in a newly formed planet or asteroid according to density. This happens when the object becomes molten.

A) Accretion
B) Differentiation
C) Condensation
D) Outgassing
E) Sublimation

Answer 3

Differentiation

Question 4

The iron in our solar system was created from smaller mass atomic nuclei in ______.

A) the Earth
B) our sun
C) Jupiter
D) the Big Bang
E) supernovas

Question 5

The first small solid grains or flakes formed in our solar system by the process of ____, the addition of material to an object an atom or molecule at a time.

A) Accretion
B) Sublimation
C) Hydration
D) Condensation
E) Vaporization

Question 6

Accretion is

A) the adding of material to an object an atom or molecule at a time.
B) the adding of material to an object by collection of solid particles.
C) the release of gas from rocks as they are heated.
D) the largest of the Galilean satellites.
E) caused by the bombardment of the solar wind.

Question 7

The Jovian problem refers to

A) the high speed with which the Jovian planets rotate on their axes.
B) the large number of satellites that orbit each Jovian planet.
C) the existence of rings around the Jovian planets.
D) the excess heat radiated by the larger of the Jovian planets.
E) the apparently short period of time that disks exist around stars from which Jovian planets can form.

Question 8

A(n) ____ is a solar system object that enters Earth s atmosphere and becomes very hot due to friction between the object and Earth s atmosphere and does not survive to reach the surface.

A) asteroid
B) meteor
C) comet
D) meteoroid
E) planetesimal

Question 9

Which one of the following IS a characteristic of Jovian planets?

A) low average density
B) orbits inside the asteroids
C) craters in old surfaces
D) small diameters
E) very few satellites

Question 10

Protoplanets

A) grew in size primarily by accretion.
B) grew in size primarily by condensation.
C) are still visible today as the terrestrial planets.
D) grew in size by collecting the particles in the solar wind.
E) grew in size by the collision and coalescing of planetesimals.

Question 11

A future news release might report that a new planet has been found around a star very similar to our sun. This newly discovered planet is claimed to have a mass 40 times that of Earth and is located nearly 25 AU from the star it orbits. Which of the following would be a reasonable prediction about this planet?
I. The planet will probably have a mean density of around 5 g/cm 3 .
II. The planet will probably have a radius of around five to ten times greater than Earth s.
III. The planet will probably have several satellites.
IV. The planet will probably have a composition that is mostly hydrogen and helium.

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

Question 12

The oldest rocks found on Earth are about ____ years old.

A) 14 billion
B) 10.5 billion
C) 7.0 billion
D) 3.9 billion

Question 13

A newly formed planet or large asteroid becomes molten due to ______.

A) the last infalling objects
B) decay of radioactive element isotopes
C) Both of the above
D) None of the above. Newly formed planets remain solid inside

Question 14

The first solid grains of ______ formed in hot regions near the sun. Much farther from the sun the first grains (or rather flakes) of ________also formed by a similar process as the close-in grains, _______.

A) water ice; iron; accretion
B) iron: water ice; accretion
C) water ice; iron; condensation
D) iron; water ice; condensation

Question 15

Which one of the following IS NOT a characteristic of terrestrial planets?

A) low average density
B) orbits inside the asteroids
C) craters in old surfaces
D) small diameters
E) very few satellites

Question 16

An extrasolar planet is

A) a planet that orbits our sun that we have not yet discovered.
B) one not needed for the formation of our solar system which is kept in a special area just in case.
C) a planet found orbiting around a star other than the sun.
D) another name for an asteroid.
E) a planet extra close to our sun.

Question 17

____ are located beyond the asteroid belt (3 AU) from the sun, have extremely large masses and very low densities.

A) Comets
B) Extrasolar planets
C) Asteroids
D) Terrestrial planets
E) Jovian planets

Question 18

____ pushed gas and dust particles out of the solar nebula by the light from the sun.

A) Radiation pressure
B) Outgassing
C) Condensation
D) Accretion
E) Differentiation

Question 19

The satellites discovered by Galileo

A) orbit the planet Jupiter.
B) orbit the terrestrial planets.
C) orbit asteroids.
D) orbit Mars.
E) orbit extrasolar planets.

Question 20

Outgassing is

A) the adding of material to an object an atom or molecule at a time.
B) the adding of material to an object by collection of solid particles.
C) the release of gas from rocks as they are heated.
D) the largest of the Galilean satellites.
E) caused by the bombardment of the solar wind.

Question 21

The planets all lie in nearly the same plane resulting in a disk-like structure for the solar system. This disk-like structure is believed to exist because

A) the solar nebula from which the planets formed had a disk-like structure.
B) the bipolar flow from the young sun cleared all material out of the nebula except that in the disk.
C) Jupiter s gravity was great enough to pull all of the other planets to the plane of its orbit.
D) the Milky Way Galaxy from which the planets condensed has a disk like structure

Question 22

Condensation in the solar nebula probably led to the formation of

A) icy grains beyond the present orbit of Jupiter.
B) metallic grains near the present orbit of Mercury.
C) silicate grains near the present orbit of Earth.
D) all of the above
E) none of the above

Question 23

The condensation sequence suggests that ____ should condense as solids closest to the sun.

A) hydrogen and helium
B) metals and metal oxides
C) silicates
D) ices of water, methane, and ammonia

Question 24

Based on current observations, ____ has a heavy element core, and a very compressed liquid layer and atmosphere both made mostly of hydrogen.

A) Jupiter
B) Pluto
C) Venus
D) an asteroid
E) a meteor

Question 25

Once a terrestrial planet had formed from a large number of planetesimals, heat could have melted it and allowed it to differentiate into metallic core of ____density and a rocky mantle or crust of ______ density.

A) higher; lower
B) lower; higher
C) Wrong! The interior stays solid
D) Wrong! There is no separation according to density.

Question 26

If a star is found with five planets orbiting it, and a process like that described in the solar nebula theory formed the planets, which of the planets would be expected to have the greatest uncompressed density?

A) The one farthest from the star.
B) The one with the greatest mass.
C) The one with the greatest radius.
D) The one closest to the star.
E) The one that has liquid water on its surface.

Question 27

The uncompressed density of a planet in our solar system

A) is greatest for the Jovian planets.
B) is greatest for the planets closest to the sun.
C) is greatest for the planets furthest from the sun.
D) is greatest for the planets with the largest mass.
E) is greatest of the planet with the largest radius.

Question 28

The large planetesimals would have grown faster than the smaller planetesimals because

A) they were moving faster in their orbits than the smaller planetesimals.
B) their stronger gravity would pull in more material.
C) there was more material located near them that could be accreted.
D) the smaller planetesimals were covered by a layer of material that was lost during collisions.
E) all of the above

Question 29

The speed of the solar wind is approximately 400 km/s and the distance from the sun to Saturn is 9.5 AU (1 AU = 1.5 10 8 km). How long does it take a particle in the solar wind to reach Saturn?

A) about 4.1 hours
B) about 4.1 days
C) about 41 days
D) about 4.1 years
E) about 41 years

Question 30

51 Pegasi is important because

A) it is a pulsar with planets orbiting around it.
B) it is a star with a planet that is known to support intelligent life.
C) it is the largest satellite of Jupiter.
D) it is the largest known asteroid.
E) it is the first star like our sun that was found to have a planet orbiting it.

Question 31

Protoplanets of the Jovian planets could have grown very hot from

A) heat for the sun.
B) radioactivity of light elements such as hydrogen and helium.
C) the in fall of material at high velocity.
D) tidal forces due to the sun.
E) collisions with large planetesimals.

Question 32

The terrestrial planets are thought to have formed by accreting solid planetesimals all with about the same composition. This means

A) they were initially molten forming an iron core first, then they accreted a silicate crust later.
B) they were initially molten forming a silicate core first, then they accreted an iron crust later.
C) they were initially collections of solid particles which melted then differentiated into a high density iron metal core and low density silicate crust.
D) they were initially collections of solid particles which melted then differentiated into a high density silicate core and low density iron metal crust.

Question 33

Which one of the following objects is most like the planetesimals that formed in the solar nebula?

A) asteroids
B) Earth
C) Saturn
D) Venus
E) the sun

Question 34

The most important effect in clearing the solar nebula of gas and dust was

A) impacts by planetesimals.
B) the solar wind.
C) the sun s magnetic field.
D) the asteroid belt.
E) radiation pressure.

Question 35

On a photograph of the Earth s moon, the moon measures 30 cm in diameter and a small crater measures 0.2 cm. The moon s physical diameter is 1738 km. What is the physical diameter of the small crater?

A) about 1738 km
B) about 12 km
C) about 520 km
D) about 350 km
E) about 3.5 km

Question 36

Part of the current atmosphere of Earth is believed to be

A) the remnants of the original hydrogen and helium gas from the solar nebula attracted by the protoplanet.
B) the result of the melting and vaporizing of the glaciers from the last ice age.
C) composed primarily of hydrogen and helium.
D) composed of gases that were outgassed from the heated rocks sometime after the planet formed.
E) the result of a collision between the sun and another star.

Question 37

Accretion among the grains in the solar nebula would have been aided by

A) static electricity.
B) gravity.
C) high-velocity collisions.
D) all of the above
E) none of the above

Question 38

Suppose that Mercury grew to its present size in 1 million years through the accretion of particles averaging 100 g each. On average how many particles did Mercury capture each second? Note: Mercury has a mass of 3.3 10 23 kg and a radius of 2439 km.

A) about 24 particles per second
B) about 3.3*10²¹particles per second
C) about 67 particles per second
D) about 100 million particles per second
E) about 100 billion particles per second

Question 39

The diagram below illustrates the radioactive decay of Potassium ( 40 K), which has a half-life of 1.3 billion years. If a lunar rock is found that currently contains 5 grams of 40 K, and it is determined that the sample contained 20 grams when it was formed, how old is the lunar rock?

A) 6.5 billion years
B) 19.5 billion years
C) 2.6 billion years
D) 3.9 billion years
E) 4.6 billion years

Question 40

The age of the solar system is believed to be approximately 4.6 billion years based on the data from

A) samples of lunar rocks.
B) samples of Earth rocks.
C) samples of meteorites.
D) all of the above
E) none of the above

Question 41

The Jovian planets have lower average densities than the terrestrial planets.

Question 42

How is the presence of space debris accounted for by solar system models?

A) Space debris is left over material from the early solar system that never formed into a planet.
B) Space debris was formed by the collision of objects after the planets formed.
C) Space debris is material that existed in our region of space before the sun formed.
D) Both a and b
E) All of the above

Question 43

What observation made of other stars seems to suggest the solar nebula hypothesis is correct?

A) Stars are found to exist more often in binaries than by themselves.
B) Protostars are seen to radiate much of their light at infrared wavelengths.
C) Nearby stars tend to be low mass red dwarfs.
D) Young stars are found to have hot disks that surround them.

Question 44

Observations in the infrared have detected dusty nebulae around T Tauri stars.

Question 45

Compared to the terrestrial planets, Jovian planets

A) have a higher density.
B) have a smaller number of moons.
C) have a much larger diameter.
D) are much hotter.

Question 46

A planet found orbiting a star other than the sun is called a(n) ____________________.

Question 47

How is radioactive dating used to determine the age of an object?

A) Both the amounts of radioactive and decay material are measured. Using these with the radioactive material s half-life, the age can be estimated.
B) The amount of radioactive material is measured. Using this with the radioactive material s half-life, the age can be estimated.
C) The amount of decay material is measured. Using this with the radioactive material s half-life, the age can be estimated.
D) The amount of heat generated by radioactive dating is measured to determine age.

Question 48

The solar nebula theory is NOT able to explain which of the following observed characteristics of the solar system? Another theory would be needed.

A) Common direction of rotation of the planets.
B) Common direction of revolution of the planets.
C) The formation of hydrogen atoms in the solar system from subatomic particles.
D) The density of the Jovian planets.

Question 49

The adding of material an atom at a time to create a solid grain or flake is the process of ____________________.

Question 50

The original cloud from which the sun and planets formed had a composition rich in hydrogen and helium.

Question 51

Outgassing refers to the formation of an atmosphere by the attraction of gases from the surrounding nebula.

Question 52

The asteroid belt is found between which two planets orbits?

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

Question 53

The condensation sequence cannot explain the composition of the terrestrial and Jovian planets.

Question 54

The ____________________ planets have larger radii than the ____________________ planets.

Question 55

The description large somewhat dirty snowball model fits the physical structure of ____________________.

Question 56

The present motions of the planets were inherited from the rotation of the solar nebula.

Question 57

The oldest objects found so far in our solar system are Earth rocks that are 3.9 billion years old.

Question 58

When particles in the solar nebula grew large enough, they stopped growing by accretion and began growing by condensation.

Question 59

The diagram below shows the radioactive decay of cesium ( 135 Cs). What is the half-life of 135 Cs?

Question 60

The ____________________ of a radioactive substance is the amount of time for the substance to be reduced by half.

Question 61

How does the solar nebula theory explain the present densities and chemical compositions of the planets?

Question 62

Describe four effects that helped to clear the solar nebula.

Question 63

Which are the oldest solar system objects that have been dated radioactively? What are their ages?

Question 64

How did differentiation and outgassing alter protoplanets?

Question 65

What observational evidence do we have that nebulae from which planets could form surround other stars?

Question 66

How do the motions of the sun and planets reflect the disk shape of the solar nebula?

Question 67

How does the solar nebula theory account for the presence of comets?

Question 68

The pressure of sunlight was one of the forces that cleared the solar nebula.

Question 69

Describe some characteristics that all the planets seem to share and use the solar nebula theory to explain them.