The Solar System   Exam_02

------------------------------------------------------------------------------------------------------------

Answers:

01 – 10                        DBBBC             ABCBC

11 – 20                        DCDCD                        AACBC

21 – 30                        BAADB             CBDAA

31 – 40                        DBDDC                        BCDCA

41 – 50                        DAACD                        ABADD

51 – 60                        BBADA             DADCD

------------------------------------------------------------------------------------------------------------

 

1.

Suppose that in 2008, the Hubble Space Telescope discovers 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, 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

 

 

2.

Which of the following characteristics is not typical of our planetary system?

 

A)

The orbits of most planets are almost circular.

 

B)

Most planets have about the same physical size.

 

C)

The spin axes of most planets are aligned to within 30° to the perpendicular to the orbital plane.

 

D)

Most planets orbit the Sun in the same direction.

 

 

3.

The mass of the planet Jupiter is high and its atmosphere is relatively cool. What are the chances for the retention of gases within its atmosphere?

 

A)

good for light (H2 and He) molecules but poor for heavier (CH4, NH3, H2O) molecules

 

B)

good for all gases, including light (H2 and He) and heavier (CH4, NH3, H2O) molecules

 

C)

poor for all gases because of the low temperature, thus all gases will be leaving Jupiter continuously

 

D)

good for heavier (CH4, NH3, H2O) molecules but poor for light (H2 and He) molecules

 

 

4.

The asteroid belt exists between the orbits of which planets?

 

A)

Jupiter and Saturn

 

B)

Mars and Jupiter

 

C)

Venus and Earth

 

D)

Earth and Mars

 

 

5.

The region outside the orbit of Neptune in which a large number of objects composed of rock and ice circle the Sun not far from the plane of the ecliptic is called

 

A)

the Outer Solar System.

 

B)

the asteroid belt.

 

C)

the Kuiper belt.

 

D)

the Oort comet cloud.

 

 

6.

Which one of the following planets shows the greatest amount of cratering on its surface?

 

A)

Mercury

 

B)

Earth

 

C)

Mars

 

D)

Jupiter

 

 

7.

The low average densities of the Jovian planets, which have high masses and hence high gravitational fields, is an indication that their interiors are

 

A)

gaseous and have not condensed to liquid or solid form.

 

B)

composed mainly of very light elements, such as H and He.

 

C)

composed of nothing, i.e., a vacuum.

 

D)

composed of H2O, CH4 (methane), and NH3 (ammonia).

 

 

8.

A theory of the origin of the solar system must take into account all important general properties of the planets.  These include three of the four properties listed below.  Which one is not an important general property of the planets?

 

A)

The planets are grouped by size and composition into two general groups: terrestrial and Jovian.

 

B)

The terrestrial planets all orbit much closer to the Sun than do any of the Jovian planets.

 

C)

The outermost planet, Pluto, does not fit easily into either one of these groups.

 

D)

All of the planets orbit the Sun in the same direction and nearly in the same plane.

 

 

9.

The composition of matter in the universe can be summarized by which statement?

 

A)

About half of the mass of the universe is in the form of rocks, molecules, and planetary material, visible by infrared radiation.

 

B)

All but 2% of the mass in the universe is hydrogen and helium.

 

C)

2% of the mass of the universe is hydrogen and helium, the rest is heavier elements.

 

D)

Nobody knows because it is impossible to measure.

 

 

10.

When a rock that had initially been molten solidifies, it cannot contain any 40Ar, since 40Ar is a gas.  However, the rock does contain some 40K which is radioactive but it slowly decays into 40Ar with a half-life of 1.25 billion years.  Under these conditions, the 40Ar that results from the decay is trapped in the rock.  Suppose that the rock is subsequently found to have 1/8 microgram of  40K and 7/8 microgram of  40Ar in it.  How old is the rock (in billions of years)?

 

A)

0.125

 

B)

1.25

 

C)

3.75

 

D)

2.50

 

 

11.

The most likely mechanism for the solar system's formation is that the

 

A)

Sun captured the planets as they drifted through space.

 

B)

planets were spun out of the Sun as smaller gas clouds and subsequently condensed.

 

C)

It was designed and created about 6000 years ago.

 

D)

Sun and planets slowly condensed to their present form from a gas and dust cloud.

 

 

12.

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)

relatively slow growth of smaller objects by collisions and mutual gravitational attraction.

 

D)

capture of planets from outer space by gravity.

 

 

13.

The planetary system was probably formed from three different categories of material with different condensation temperatures (the temperature at which the material melts), gases, ices, and rocks (including metals). Which is the correct order of these materials, in increasing condensation temperature?

 

A)

rocks, gases, ices

 

B)

rocks, ices, gases

 

C)

gases, rocks, ices

 

D)

gases, ices, rocks

 

 

14.

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)

accretion of solid planetesimals containing mostly rocky material.

 

D)

gravitational condensation of gas followed by capture of solid planetesimals.

 

 

15.

The steps in the process of formation of the large, outer planets were

 

A)

gravitational condensation of hydrogen, helium, and dust in eddies or vortices in the outer solar nebula.

 

B)

accretion of cold planetesimals containing large quantities of hydrogen and helium.

 

C)

gravitational condensation of methane and ammonia gas, followed by capture of planetesimals.

 

D)

accretion of planetesimals made of rocks and ices to form a core, followed by gravitational capture of hydrogen and helium gas.

 

 

16.

The Oort cloud is

 

A)

a spherical solar system halo of icy objects far beyond the orbit of Pluto.

 

B)

a flat region just outside the orbit of Neptune in which icy and rocky objects circle the Sun.

 

C)

the collection of rocky objects orbiting the Sun between the orbits of Mars and Jupiter.

 

D)

a type of cumulo-nimbus cloud that forewarns of a large storm.

 

 

17.

Strong evidence for the existence of planetary systems around other stars comes from

 

A)

periodic wobbling of the positions and spectral line positions of several nearby stars.

 

B)

direct photography of actual planets near other stars.

 

C)

spectroscopic evidence of large quantities of molecules such as ammonia and methane, which can only exist in planetary atmospheres.

 

D)

close encounters of the third kind.

 

 

18.

What is surprising about the extrasolar planets that have been discovered?

 

A)

More than half of them have strong lines of molecular oxygen in their spectra, a possible indication of life on these planets.

 

B)

The majority of them rotate much faster than the planets in our solar system.