1. Earth Facts

2. What is the Shape of the Earth? The earth’s shape is an Oblate Spheriod. Not an exact globe, it bulges at the center 24,899 miles at equator 24,817 miles at polar circumference Caused by rotation on axis Like a pumpkin

3. Earth’s Rotation Spin on its axis Causes night and day Contributes to shape 1600 km/hr (1000 mi/hr)

4. Earth’s orbital speed 29.6 km/sec (18.5 mi/sec) Causes the length of our year

6. Earth’s Age 4,600,000,000 years old (4.6 billion years) Evidence Radioactive decay Carbon dating Fossils Rock layers Isotope dating Superposition GPS tracking Oldest rocks 3.5 billion years (northeast Canada) 3.5 billion Northern Michigan

7. Early estimates 6,000 years – biblical esitmate Physicists started calculating around the year 1700.

8. Earth’s Diameter 8000 miles or 12,734 km

9. Distance from sun: Average of 93,000,000 miles (93 million) We are closer to the sun in the winter!

10. Tilted Axis Tipped 23.5 degrees on its axis to its plane of orbit. This causes the 4 seasons.

11. Earth’s Mass 6,000,000,000,000,000,000,000 tons Pronounced Six sextillion tons (calculated using Newton's law of gravitation) Average density = 5.52 g/cm 3 Density = mass/volume