Astronomy
Seasons PPT Notes
Name ___________________KEY____________________
1. What is rotation? How long does it take (for Earth)?
Spin on axis; 24 hours = 1 day
2. What is revolution? How long does it take (for Earth)?
Orbit around Sun; 365 ¼ days = 1 year
3. The tilt of Earth’s axis is equal to ___23.5___ degrees.
4. Earth’s axis ALWAYS points to the star named __Polaris______.
5. The celestial equator is __23.5__ degrees from the ecliptic.
6. “Oblique” means ______AT AN ANGLE_____________. Oblique rays are __COOLER__.
7. Ecliptic is ___PLANE FORMED BY LINE BETWEEN EARTH AND SUN______________.
8. Direct rays are _____HOTTEST_____ (temperature wise); Where on Earth are the most
direct rays from the Sun? __EQUATOR_____
9. Equinox means _________EQUAL DAY AND NIGHT_______________________
10. The equinox marks the beginning of ____SPRING___ and ____FALL___ (seasons).
11. On the 2 days of the equinox, the Sun is directly over ___EQUATOR______.
12. The soltstice has the _LONGEST___ and __SHORTEST___ amount of daylight hours.
13. The solstice marks the beginning of ___WINTER___ and __SUMMER__ (seasons).
14. At the SUMMER solstice, the Sun is directly over __TROPIC OF CANCER___.
15. At the WINTER solstice, the Sun is directly over __TROPIC OF CAPRICORN____.
16. At the Equator, the Sun is almost always __DIRECTLY OVERHEAD___.
17. At the North (or South) Pole, the Sun travels ____IN A CIRCLE__ around horizon.
18. On the Summer solstice, __JUNE 21__ (date), the Sun NEVER SETS above __66.5 N__
(latitude) and never rises below ___66.5 S__(latitude).
19. On the Winter solstice, ___DEC 21__ (date), the Sun NEVER RISES above __66.5 N ___
(latitude) and never SETS below ___66.5 S ___(latitude).
20. The __ANALEMMA__ traces the path of the Sun over a year’s time.
21. On a Sundial, the gnomon’s angle equals your _LATITUDE___.
22. Name TWO reasons Earth has seasons:
1) EARTH’S AXIS IS TILTED (23.5 DEGREES)
2) EARTH REVOLVES AROUND THE SUN
Watch the BrainPop video, Solstices and Equinoxes, to help answer the following:
23. On March 20/21, the vernal equinox, all parts of the Earth receive _EQUAL SUN___.
24. At the equinox, the Sun rises and sets at _90__(angle) at the ___EQUATOR_.
25. Everywhere on Earth, except at the Poles, there are _12_ hours of day at the
equinoxes.
26. On December 21, the WINTER SOLSTICE the Northern Hemisphere is pointing the
(farthest or closest) from/to the Sun.
27. People at the Equator have about ___12_ hours daylight all year round.
28. The word solstice means _____SUN STANDS STILL______. Literally, this means that the
Sun (changes or does not changes) positions as much at this time.
Watch BrainPop, The Seasons:
29. What would happen to seasons if the Earth were NOT tilted?
THERE WOULD BE NO seasons.
30. On which dates do the seasons begin in Northern Hemisphere:
Spring (vernal equinox) ____MARCH 20 OR 21_____
Summer ____JUNE 21______
Fall (autumnal equinox) _____SEPTEMBER 21 OR 22____
Winter ____DECEMBER 21________