1. Earth’s Motion(Chapter 4) The Moon (Chapter 25)

2. Time Zones
The Earth takes 24 hours to rotate once on its axis. Therefore, the Earth has been divided into 24 Time Zones.
Time Zones are a geophysical world globe division of 15o each, starting at Greenwich, England, created to help people know what time it is now in another part of the world (see page 76 in your text for a good Time Zone tool).

3. Prime Meridian
Time Zones to the west of the Prime Meridian are behind Greenwich Mean Time (GMT, UTC)
Time Zones to the east of the Prime Meridian are ahead of GMT

5. International Date Line
Separates two calendar days at 180˚ longitude
(“on the other side” of the Prime Meridian)
Immediately to the left is the eastern hemisphere which is always one day ahead of the western hemisphere to the right
The line bends in order to include all of Kiribati and other Pacific Island Nations

6. I N T E R A O l D A T E L I N e

8. Equinoxes
two days per year midway between solstices
daytime & nighttime are equal all over world
sun is directly over the noon
vernal equinox (first day of sprint): March 21
autumnal equinox (first day of fall): September 22

9. Chapter 25 Earth’s Moon

10. 25.1 Origin & Properties of the Moon
4 theories of origin:
1) Earth and moon formed simultaneously
2) Fission: Earth spun so fast that a chunk spun off into orbit
3) Capture: moon formed elsewhere and was caught by Earth’s gravity

11. Origin of the Moon
4) Impact Theory – planet sized object collided with Earth and debris settled into orbit, pulled together and formed the moon
** This is the currently accepted theory!

13. Features of the Moon
Maria: large, dark areas formed from early lava flows
Terrae (highlands): older, lighter areas of the moon with more craters
Impact Craters: formed from meteorites
Weathered and eroded by micrometeorites
No atmosphere!

14. 25.2 The moon’s motions Orbits the Earth in 27 1/3 days
Orbit shape is elliptical
Perigee=nearest to Earth
Apogee=farthest from Earth
We see the same side of the moon because the Moon’s orbit around Earth takes just as long as one rotation on its axis!
Orbital period = rotational period

15. Moon’s Phases

16. Lunar Eclipse Moon enters Earth’s shadow
Can only occur at a full moon phase
Umbra=total shadow
Penumbra=partial shadow
Moon appears orange

17. Solar Eclipse Occurs when moon comes between the sun and Earth
Occurs only at the new moon phase
Total time = 7.5 min
Moon is dark, but sun’s corona is visible around the moon making a gold ring