1. Unit 8 Earth in Space
Seasons and Tides

2. The reasons for the seasons
Fall Equinox
Summer Solstice
Spring Equinox
Winter Solstice

3. The reasons for the seasons
Earth’s Tilt
Fall Equinox
Summer Solstice
Spring Equinox
Winter Solstice
SUN

4. Equinox Solstice Ecliptic Plane
When the days and nights are ~ equal length (March and September) When Sun is furthest or closest to the Earth’s poles The plane in which the planets in our solar system orbit the Sun

5. Aphelion Perihelion
When Earth is furthest from Sun with slowest revolution When Earth is closest to Sun with fastest revolution

6. Bell Work: How will precession affect the seasons?
Fall Equinox
SUN
Summer Solstice
Spring Equinox
January 2015
January 15,015

7. Earth And its Moon The Moon Orbits the Earth once every 27.3 days.
The Moon and Earth orbit about the barycenter

8. Lunar Eclipse
When the Moon is FURTHEST from the Sun and on the ecliptic plane

9. Solar Eclipse
When the Moon is CLOSEST to the Sun and on the ecliptic plane

10. Earth And its Moon
Gravity from the Moon and Sun cause ocean tides on Earth
When Sun-Earth-Moon are lined up the tides are the highest and the lowest.

11. When Sun-Earth-Moon form a right angle the high tides are at their lowest and the low tides are at their highest.

12. Spring Tides: When Earth, Sun and Moon are aligned; during full and new moons

13. Neap Tides: When Sun and Moon form right angles to Earth; during quarter moons

14. Diurnal Tides
1 high tide and 1 low tide each lunar day. (1 lunar day = 24hrs 50min)
Seen in many areas of the Gulf of Mexico

15. Semi-diurnal Tides
2 high tides and 2 low tides of equal size each lunar day.
Seen along the East Coast of N. America

16. Mixed Semi-diurnal Tides
2 high tides and 2 low tides of unequal size each lunar day.
Seen along the West Coast of N. America

18. First Quarter Moon
New Moon
Third Quarter Moon