earth facts. what is the shape of the earth? the earth’s shape is an oblate spheriod. not an exact...

Earth Facts

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

Earth’s Rotation

Spin on its axis

Causes night and day

Contributes to shape

1600 km/hr (1000 mi/hr)

Earth’s orbital speed

29.6 km/sec (18.5 mi/sec)

Causes the length of our year

Earth’s Age4,600,000,000 years old

(4.6 billion years)

EvidenceRadioactive decay

Carbon dating

Fossils

Rock layers

Isotope dating

Superposition

GPS tracking

Oldest rocks3.5 billion years (northeast Canada)

3.5 billion Northern Michigan

Early estimates

6,000 years – biblical esitmate

Physicists started calculating around the year 1700.

Earth’s Diameter

8000 miles or 12,734 km

Distance from sun:

Average of 93,000,000 miles(93 million)

We are closer to the sun in the winter!

Tilted Axis

Tipped 23.5 degrees on its axis to its plane of orbit.

This causes the 4 seasons.

Earth’s Mass

6,000,000,000,000,000,000,000 tonsPronounced Six sextillion tons

(calculated using Newton's law of gravitation)

Average density = 5.52 g/cm3

Density = mass/volume