The Sun-Earth-Moon System Folder: All notes pertaining to Earth and Environmental will be kept here
Earth’s Shape Earth is sphere shaped Aristotle reasoned this because round shadows were being cast on the moon during eclipses. Other evidence came through sailors that would see the tops of the sail masts as they came over the horizon. Today we have satellite imagery to give us real shape. It is spherical shaped as it bulges out around the equator area and the poles are somewhat flattened.
Physical Properties of Earth Diameter (pole to pole) 12,714 km Diameter (equator) 12,756 km Circumference (poles) 40,008 km Cirumference (equator) 40,075 km Mass 5.98 X 10 27 g Density 5.52 g/cm3 Average distance to sun 149,600,000km Period of rotation (1 day) 23 hr, 56 min Period of Revolution (1 year) 365 day, 6 hr, 9 min
Poles ~ Earth has poles, northern and southern. ~ They fall along the imaginary line called the axis. ~ The spinning of Earth on its axis, called rotation, causes day and night to occur.
Earth Rotation As Earth rotates the sum comes into view at day break. Earth continues to move, giving illusion that sun is moving until sun set Earth Continues to move even through the sun is not visible Again: Day/Night Effect