Earth Rotation & Revolution

1. Earth Rotation & Revolution Physical Geography 10

2. Earth Rotation • The earth rotates on its axis a full 360 degrees every 24 hours. • This causes the difference between night and day.

3. Earth Revolution • Earth makes a complete revolution around the sun every 365 and 1/4 days. • This revolution and the tilt of the earth, paired with the sun, causes the changes of the seasons.

4. Leap Year • We have a leap year every 4 years to make up for that ¼ of a day that isn’t accounted for on our calendar. • This is to ensure that our seasons match up with our calendar. This year is a leap year!!

5. What is the Relationship between Earth and the Sun • The sun, in combination with earth’s axis is responsible for the length of day as well as difference in temperature.

6. How Seasons Occur • The angle of the Earth's axis means that at different points on its orbit around the sun, different parts of the earth are tilted toward the sun. • The part that is tilted toward the sun is the part that is having summer. If the northern hemisphere is tilted toward the sun, the northern hemisphere receives the most direct rays of the sun and it is summer in the northern hemisphere.  • If the southern hemisphere is tilted toward the sun, the southern hemisphere receives the most direct rays of the sun

7. Summer and Winter Solstice

8. Summer & Winter Solstice • Tropic of Cancer – 23.5 degrees north of the equator • Tropic of Capricorn – 23.5 degrees south of the equator • A solstice is an astronomical event that happens twice a year, when the tilt of the Earth's axis is most oriented toward or away from the Sun • Winter Solstice – December 21/22 • Summer Solstice – June 20/21

9. Equinoxes • Equinoxes occur twice a year, when the tilt of the Earth's axis is oriented neither from nor to the Sun, causing the Sun to be located vertically above a point on the equator. • The subsolar point on a planet is where its sun is perceived to be directly overhead (zenith)