Sample Old Exam 16

Rules for this exam: This examination is to be taken without help of books or papers or notes. It is to be worked on individually; the Vanderbilt Honor Code applies. You may use calculators (although I don't expect you to need them). Please write clearly.

General test-taking advice for this exam: Below, you will find 27 fill in the blank, true/false and multiple choice questions worth a total of 54 points (out of 100).  These should take you 20-25 minutes. Questions 28-30 require written answers of at least several sentences. While I don't expect you to write a book in a time-limited exam setting, I expect concise, logically complete answers.


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1.  [2 pts] The rings of Saturn occupy the region inside Saturn's __________________.
2.  [2 pts] When the Sun uses up the nuclear fuel in its core and reaches the end of its
                  lifetime as a regular star (in about 5 billion years), it will become
                 a    ______________________.
3.  [2 pts] Saturn's rings are composed primarily of ______________________.
4.  [2 pts] Jupiter and Saturn have large equatorial bulges because they
                  _________________________ .
5.  [2 pts] Planets in binary star systems (or in a Sun-Jupiter system in which Jupiter was
                much more massive) are not considered habitable because the planetary orbits
                are often    ___________________.
6. [2 pts] True or False: Saturn probably does not have a rocky core.
7.  [2 pts] True or False:  Titan's atmosphere is thicker and denser than Earth's
                atmosphere.
8.  [2 pts] True or False: Funding for NASA ($13 Billion in FY 2000) makes up less
                 than 1% of the federal budget.
9.  [2 pts] True or False: Water ice accounts for as much as half of the mass of the
                Jovian moons Europa and Callisto.
10.  [2 pts] True or False: Conditions that could support life (energy source, liquid
                 water) exist in the global oceans on the surface of Europa.
11. [2 pts] True or False: Water is relatively common among the terrestrial planets but
                 uncommon among the moons in the outer solar system.
12. [2 pts] True or False: The most volcanically active object in the solar system is Io.
13. [2 pts] True or False: Organic molecules are known to only exist on Earth.
14. [2 pts] True or False: The Viking landers on Mars (1976) discovered microscopic
                 evidence of life but found no large fossil evidence.
15. [2 pts] Saturn's rings
    A. are debris left over from the formation of Saturn and the Saturnian moon system
    B. contain less mass than a small shepherd satellite (50 km in diameter)
    C. from the erosion of material off the surface of the moon Tethys
    D. are the debris from a catastrophic collision that occurred less than 100 million
          years ago.
16. [2 pts] Chemically-based life is less likely to be based on silicon than on carbon
       because
      A. silicon is not dissolvable in water
      B. silicon cannot bond with hydrogen
      C. silicon's chemical bonds are stronger than carbon's
      D. silicon's chemical bonds are weaker than carbon's
17. [2 pts] Which of the following parameters in the Drake Equation do we have
       sufficient data on such that the value we might assign when calculating the Drake
       equation goes beyond pure speculation?
      A. the number of habitable planets per planetary system
      B. the fraction of habitable planets on which life arises
      C. the rate of star formation
      D. the average lifetime of a technological civilization
      E. the fraction of life-bearing planets on which intelligence arises
18. [2 pts] The energy that powers volcanic activity on Io comes from
      A. radioactive decay of radioactive elements inside Io
      B. the gravity of Jupiter
      C. the tidal influence of Jupiter in combination with the gravitational
           influence of Europa
      D. ultraviolet light from the Sun
      E. Jupiter's magnetosphere
19. [2 pts]  Visual observations of Jupiter reveal it exhibits differential rotation.  This
       demonstrates that Jupiter
      A. has a magnetic field.
      B. has no solid surface.
      C. rotates extremely fast.
      D. has a pronounced equatorial bulge.
20. [2 pts] Ganymede (diameter = 5270 km; mass = 2.02 Moon masses) and Titan
      (diameter = 5150 km; mass = 1.83 Moon masses) have nearly identical sizes and
      masses and thus nearly identical escape velocities.  Yet Titan has an atmosphere
      and Ganymede does not. This is largely because
      A. of the influence of Jupiter's strong magnetic field on Ganymede
           compared to the weaker influence of Saturn's weaker magnetic
           field on Titan
      B. the presence of ring material from Saturn's rings, from which
          Titan collects material for its atmosphere
      C. Saturn is twice as far from the Sun as is Jupiter
      D. of catastrophic events in the history of the solar system.
       
21. [2 pts] Jupiter is "too hot," at 125 K rather than 105 K at its cloud tops.  This is
      because
      A. Jupiter is rich in radioactive material
      B. Jupiter is a brown dwarf, generating a very small amount of
           energy from nuclear fusion
      C. Jupiter is still shrinking
      D. Jupiter absorbs sunlight effectively at the equator and transfers
           that energy to the cloud tops near at polar latitudes.
22. [2 pts] Saturn's rings should naturally spread out with time due to collisions among
      ring particles, causing the gradual and irreversible erosion of the rings. However,
      A. shepherd satellites and the moon Mimas hold the rings in place
      B. shepherd satellites hold the rings in place.
      C. Saturn's magnetic field holds the rings in place.
      D. orbital resonances with Titan hold the rings in place.
23. [2 pts] Saturn's moon Enceladus is unusual because
      A. rather than rotate on it's axis, it tumbles irregularly
      B. it has small moons 60 degrees ahead of and behind it in it's orbit,
          at the Lagrange points
      C. it is two-faced, with a dark side and a bright side
      D. has few impact craters and is extremely shiny, probably because it
           is coated in fresh ice crystals  from water volcanism
24. [2 pts] Jupiter and Saturn are composed mostly of
      A. hydrogen and helium
      B. noble gases
      C. liquid metallic hydrogen
      D. 10 earth masses of rock and iron
25. [2 pts] The object with the youngest surface in the solar system is
      A. Io
      B. Earth
      C. Europa
      D. Mars
26. [2 pts] Saturn's rings are amazingly flat. The ratio of width (diameter, in meters) to thickness (height, in meters) of Saturn's rings is close to
      A. 2,000 : 200
      B. 200,000 : 200
      C. 200,000,000 : 200
      D. 200,000,000,000 : 200

 

27. [2 pts] Saturn radiates three times as much energy as it absorbs from the Sun.  Saturn's energy source is

      A. helium rain.
      B. radioactivity.
      C. nuclear fusion.
      D. a mageto-dynamo.


28.  [15 pts]  In the light of recent events at NASA (e.g, the loss of Mars Polar Lander [$150 M] last week, the loss of Mars Surveyor 98 Orbiter [$150M] earlier this fall, the loss of Mars Observer in 1993 [$1.5 B]; e.g., the successes of the Galileo mission to Jupiter [$1.5 B], the Mars Pathfinder [$150 M] and Global Surveyor [$150M] missions in 1997, the Hubble Space Telescope [$4 B]), write an  editorial for the Opinion page of The Hustler in which you take a position either criticizing the continued expenditure of funds on space exploration or commending the efforts of NASA and encouraging continued support for space exploration.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

29. Our basic model for the formation of the solar system is very successful at
      explaining almost all known features of our solar system.
a) [5 pts] briefly describe the basic model for the formation of the solar system
b) [5 pts] briefly explain which fundamental features of the solar system are well
     explained by this model
c) [5 pts] briefly explain why the discovery of the extrasolar planets found thus far don't
    match this model for planet formation and how astrophysicists have improved the
    model to account for existence of these planets
d) [5 pts] briefly explain why the discovery that Jupiter's atmosphere has 2.5 times as
     much argon, krypton and xenon as the Sun requires improving this model yet again
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

30. [10 pts] How do we explain the densities of the four main moons of Jupiter?
     [Data for Jupiter's four main moons are given in the table below. ]
 

Moon Distance from Jupiter Orbital Period Diameter Mass Density
Io 422,000 km 1.77 days 3640 km 1.22 Moon masses 3.5 gm/cc
Europa 671,000 km 3.55 days 3130 km 0.65 Moon masses 3.0 gm/cc
Ganymede 1,070,000 km 7.15 days 5270 km 2.02 Moon masses 1.9 gm/cc
Callisto 1,880,000 km 16.7 days 4800 km 1.46 Moon masses 1.9 gm/cc