Exam 1 answers -- Spring 2012


There were two multiple choice versions.  You can see which one
matches the right answers or look at choice C on Question 1 to
find out which version you had.


Multiple Choice

          1 11111 11112 22222 222
12345 67890 12345 67890 12345 678
----- ----- ----- ----- ----- ----- -----
CEAAB CDEED DAAAE CBBCB BDDBB BBC   (Question 1
                                     C. 26,000) 

DDBAB DCEEE BAABC BBBAB CCDBB BCC   (Question 1
                                     C. 13,000)


Short answer questions 

29. What specific steps would you have to take if you wanted a 
    chance to see the next total solar eclipse?

    Consult you favorite archive of upcoming total solar eclipses and
    find the prediction for the path of the Moon's umbral shadow
    across the Earth for that event.   Place yourself at
    some point on the path at the right time.

    Note that making it clear that there was a "path" of viewing
    options rather than being at a singular "spot" was considered
    one (picky) point of the scoring.

36.  On the sketch below label the North and South celestial poles
(with an "N" and "S"), the celestial equator, and the ecliptic.  Use
an arrow to note the direction of motion of the Sun along the Ecliptic
and mark the Vernal (Spring) Equinox.


      See this figure from the lecture notes.

     You lost 1 point for mis-identifying the vernal (spring) equinox.
     Since you indicated a direction for the Sun's motion along the
       ecliptic the Vernal Equinox is the point at which the Sun
       would cross from the southern hemisphere into the northern hemisphere.

     You lost 2 points for mixing up the celestial equator and ecliptic.


31.  LIST a few observations you could make to determine whether an object you see up in the sky is likely a planet rather than a star.

    - Found near the ecliptic (or the celestial equator as an approximation
         to the ecliptic)   -- you had to have this one to get full credit
    - Brightest things in the sky.
    - Will move with respect to the stars night-to-night
    - Stars twinkle planets don't (usually)

     Three of these (if they included the first) would get you full
       credit.


32.   Define each of the following in a few words and certainly in no more than one short sentence.

     Circumpolar star -  a star close enough to the celestial pole that it
      never sets below the horizon.

     Asterism - a commonly recoginzed pattern of stars, often part of
                a constellation or spanning constellations.

     Synodic month  - the time from one new moon to the next, the time
       it takes the moon to complete an orbit around the Earth with respect
       to the Sun.

    Opposition - When Earth is between a superior planet and the Sun.

    Zodiac - The twelve constellations through which the ecliptic/Sun passes.