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. Please write clearly.

General test-taking advice for this exam:  The first 8 questions ask for very short answers, without explanations. Be very brief and to the point. Longer answers are expected for questions 9-15.  Each question has an assigned point value (in brackets), with the points totaling 100 for the exam.  While I don't expect you to write a book in a time-limited exam setting, I expect logically complete, though concise, answers.  Correct but incomplete answers, or incorrect answers with correct logical support will receive varying degrees of partial credit.

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1. [9 pts] What three criteria [list them] did we agree are necessary conditions for defining an object as a planet?

 
2. [3 pts] Why are Centaurs, like Chiron, on unstable orbits?

 
3. [3 pts] What is the approximate size (diameter) of a typical comet?

 
4. [3 pts] What is the most abundant material in a typical comet?

 
5. [3 pts] Where is theKuiper Belt located?

 
6. [3 pts] Where is the Asteroid Belt located?

 
7. [3 pts] Approximately when were the first Kuiper Belt objects discovered?

 
8. [3 pts] Approximately when were the first Asteroid Belt objects discovered?

 
9. [10 pts] We classify meteorites into three distinct classes: irons, stoney-irons, and stones. How do we explain how these three broad classes of meteorties formed? In this regard, what is the significance of the Allende meteorite?

 
10. [10 pts] Why, on Sept 23, 1846, did the German astronomer Johann Galle, working at the Berlin Obsevatory, discover Neptune?

 
11. [10 pts] For over 20 years, the distinguished astronomer Sir Fred Hoyle and his colleague Chandra Wickramasinghe have argued that the great flu pandemics are caused by flu viruses that originate in comets.  These viruses, they claim, are swept into Earth's atmosphere as the Earth passes through the tails or orbital paths of comets. The idea that flu viruses originate in comets is very far out of the scientific mainstream and Hoyle and Wickramasinghe have almost no supporters in the scientific community.  Is this idea completely flawed or can you suggest any reasons why this theory should be taken seriously?

 
12. [10 pts] List (do not explain) five lines of evidence that demonstrate that an asteroid impact event occurred 65 million years ago, at the approximate time of the demise of the dinosaurs (the Cretaceous-Tertiary boundary). For one of these five - but not including the crater itself - explain the logical connection between an impact event and this piece of evidence.

 
13. [10 pts] The most recently discovered object in the solar system, now named "2001 DC77," was identified on February 20, 2001.  This object has a semi-major axis a = 2.7 and an eccentricity e=0.5. Into what group of solar system objects would we classify 2001 DC77, and why would you classify 2001 DC77 in this way?

 

 
 
 
 

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14. [10 pts] The Titius-Bode formula, developed in the 1760s, is an attempt to explain the physical spacings of the planets' orbits (i.e., the sizes of their orbital semi-major axes).  The Titius-Bode formula can be written as distance = 0.4 + 0.3 x 2ⁿ, where distance is in units of AU and "n" is the planet number, ignoring Mercury and starting with Venus (n=0, 2ⁿ=1, distance=0.7), Earth (n=1, 2ⁿ=2, distance=1.0), Mars (n=2, 2ⁿ=4, distance=1.6), etc.  In the 1760s, what did the Titius-Bode formula predict that was not already known? The Titius-Bode formula was experimentally tested over the following two centuries.   What were the outcomes of these tests and what do the test results tell us about the value of the Titius-Bode formula?

 
15. [10 pts] Comet Halley, which orbits the Sun in about 76 years, was losing mass at the rate of about 54 tons per second as it passed through the inner solar system in 1986.  What conclusions can we draw about comets and the solar system from this single measurement of the mass loss rate from Comet Halley? You must provide some explanation to justify your answer.

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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