Characteristics and Origins of the Solar System

First Hour Examination

September 25,2000

 

Write in complete sentences.  Describe what it is you are trying to do, or what idea you are developing.  Walk with Ursus!

 

  1. The orbits of planets around the Sun can be described by a certain mathematical figure.  What is this figure, and what is the scientific term for the law that says this is so?  Make a rough, Cro-Magnon-like cave drawing representation of this figure, and indicate some of  its important features.
  2. You have been abducted by space aliens!!!  They take you to their secret laboratory in orbit around the Earth where they keep their time machine.  They put you in and turn on the power. When you come out, you look out the porthole of the space laboratory and watch the Earth below you for a while.  You soon realize that they have sent you back 250 million years in the past!  How could you know that?
  3. Define the terms  sidereal day  and  mean solar day.  Explain why they are different. Be quantitative.
  4. A comet has an orbital period of 127 years. At its closest approach to the Sun (perihelion) it is at a distance of 0.50 astronomical units. How far from the Sun is it at aphelion, when it is most distant?
  5. Explain why the 5° inclination of the Moon’s orbit is important in determining the occurrence of eclipses. 
  6. Define what is meant by astronomical unit and give its value (at least roughly).

 

 

These might be handy (however inclusion does not necessitate their use)

(1)   a3  =  P2  

(2)   N(t) = N0 e-0.693 t/T