1. Time Zones & Ellipse Pathway Objective: To map out the Earth’s time zones and draw the ellipse orbit around the sun with equinoxes and solstices.

2. Research Rotation of Earth: Spinning of earth on its axis every 24 hours. Time Zones of Earth: Earth is divided into 24 time zones because different parts of earth are exposed to sun at different times during rotation. Prime Meridian: Starting point for time zones= longitude line going through Greenwich, England. 12 time zones to the West of Prime Meridian: 5pm – 6 am 12 time zones to the East of Prime Meridian: 6pm – 5 am

3. Research, continued…. International Date Line: Longitude line through Pacific Ocean. When you cross it moving West, you add a day. Moving East, subtract a day. Daylight Saving Time: Some states use this from March to October. Set clocks 1 hour ahead of their time zone. Leap Year: Add a day every 4 years to account for 365 ¼ day for revolution.

4. Research Earth revolves around the sun in an orbit shaped like an ellipse: oval Brightness of Mars as seen from Earth: varies because distance varies. Earth is closest to the sun in: winter (Northern Hemisphere) and farthest insummer. (Northern Hemisphere)

5. Winter Solstice Vernal Equinox Summer Solstice Autumnal Equinox Ellipse Pathway

6. Conclusions  How do you explain that when Earth is closest to the Sun, it is winter in the Northern Hemisphere?  The planets do not move at constant speed while moving in the elliptical orbits. A planet increases in speed as it gets closer to the Sun. What force causes this change in speed?

7. Conclusions  Which part of Earth’s revolution takes longest, from vernal equinox to autumnal equinox or from autumnal to vernal?