Astronomy
9-23-2013
Name ________KEY____________
Seasons Quiz – Study Guide 13
Facts to Know:
1. When is the Earth closest/nearest to the Sun? closest – Jan 4; farthest – July 4
2. Earth rotates _W_ to __E_ so stars, the Sun, and Moon appear to rise in the _E_ and set
in the _W_.
3. A Sundial’s inclination in Anchorage should equal __61_ degrees. (= _our latitude )
4. Number of degrees Earth is tilted _23-1/2 _ to the _ecliptic__.
5. Daylight hours appear to change the most quickly near the equinoxes (seasons).
6. What season begins when the Sun is located directly over
a. Tropic of Cancer June 21, Summer in N Hemisphere
b. Equator March or Sept 21; Spring and Fall equinoxes
c. Tropic of Capricorn Dec 21; Winter in N Hemisphere
7. What is the latitude of the Arctic Circle? _66-1/2 N_; Tropic of Cancer? __23.5 N__;
Tropic of Capricorn? __23.5 S__; Equator? __0_; Antarctic Circle? __66.5 S__
8. Number of daylight hours at the equinoxes _12_ and where? _EVERYWHERE!__
9. Two reasons why we have seasons on Earth
Earth is tilted and revolves around Sun
10. What did Foucault’s pendulum prove? Earth rotates
11. (re-read Pre-Quiz questions on Seasons Video)
12. How can you find Polaris in our sky? Include latitude and azimuth direction.
Looking North (azimuth 0 degrees), go up 61 degrees (altitude) using 6 fists.
Vocabulary
1. latitude Degrees N or S of Equator
2. solstice when Sun is highest or lowest altitude (Summer and Winter)
3. equinox when Sun is directly overhead at Equator (Fall and Spring)
4. rotation spinning on axis (on Earth, one rotation = one day)
5. revolution orbiting around larger object (planet or star) (on Earth, one rev = 1 year)
6. Polaris North polar star; Earth’s axis of rotation points directly at Polaris
7. Altitude degrees above the horizon (overhead = 90 degrees
8. azimuth angular degrees along the 360 degrees of horizon
9. zenith point 90 degrees directly overhead
10. oblique versus vertical rays (of Sun) oblique rays are at an angle and vertical rays will
produce the most heat
11. Solar Noon: time when Sun is highest in the sky (on the meridian)
12. Direct (vertical) hottest rays of sun, most intense
Be able to locate on a map:
1. Locate the Equator, Tropics of Cancer and Capricorn, Arctic and Antarctic Circles
Latitude: 0
23 1/2 N
23 1/2 S 66 1/2 N
66 1/2 S
2. Determine what season is depicted when given a Sun and tilted Earth look at the North
pole on Earth—if it is tilted towards the Sun, it is SUMMER for N. hemisphere
3. Tell how the seasons differ in N and S hemispheres they are the opposite: Summer in
the N hemisphere is Winter in the S hemisphere
4. Which parts of the Earth receive NO sunlight at which times In N Hemisphere’s winter,
areas above the Arctic Circle (66-1/2 N) get NO sunlight (Sun is directly over the Tropic
of Capricorn, 66-1/2 S)
5. Predict how our seasons would be different if we had NO tilt We would all have only
one season, and only 12 hours of daylight, all year round
6. Draw an analemma, and label significant dates.
Summer Solstice
Equinox
Winter Solstice
7. When and why did people build Stonehenge? About 2500 BC, to mark the solstices and
equinoxes
BONUS Questions (or maybe possible)
1. What is the altitude of the sun in Anchorage on Dec 21? 5.5_;
2. June 21? 55_;
3. Sept 21?_30
4. Where does the sun rise (azimuth degrees) in Anchorage on June 22?
On Dec 22? 143
On March 22? 90
32
5. Draw an analemma for Mars.
6. If the Earth were tilted at 40o , where would a Tropic of Cancer be located? __40 N___
Where would the Arctic Circle be? __50 N__
7. Why is the Tropic of Cancer called the “Tropic of Cancer” and not Tropic of “something
else?” On June 21, the Sun was located in the zodiac constellation Cancer.