The thickest of Earth's layers, which is directly above the outer core. It is composed mostly of compounds rich in iron, silicon, and magnesium.
A thin, slush like layer of the mantle that the more rigid material of the lithosphere floats upon.
The lines of magnetic force that surround the Earth and protect it from the sun's deadly solar wind.
An iron sphere on a very long wire, that gives evidence that the Earth rotates on its axis.
The apparent deflection of the winds caused by the spinning of the
Earth on its axis.
Each standard time zone which is roughly centered on a line of longitude exactly divisible by 15º.
The apparent shift in positions of nearby stars compared to distant stars. This is evidence of the Earth's revolution around the sun.
The day in which we have maximum daylight. In the Northern Hemisphere this happens around June 21.
The day in which we have the least amount of daylight. In the Northern Hemisphere this happens around December 21.
The latitude line that is 23.5º below the North Pole. Areas above this line have 24 hours of darkness on Dec. 21st
The latitude line that is 23.5º above the South Pole. Areas below this line have 24 hours of darkness on June 21st
Tropic of Cancer
The latitude line that is 23.5º above the equator. Areas on this line have the sun directly overhead on June 21st.