| A | B |
|---|
| shadows | a dark image cast on the ground by a body blocking light. |
| equinox | date on which day and night are of equal length; day=night |
| penumbra | a larger outside area of a shadow, where light is partly blocked out |
| day | When this part of the earth faces the sun, it is __. |
| night | When this part of the earth faces away from the sun, it is __. |
| rotation | The Earth turns on its axis. It causes day and night once every 24 hours. |
| revolution | the Earth goes around the sun. |
| planetary rotation | Planets turn on their axes. |
| planetary revolution | Planets go around the sun. |
| earth axis | imaginary vertical line through the center of the earth around which it rotates. |
| latitude | measure of distance north or south of the equator |
| longitude | measure of the distance east or west of the prime meridian |
| equator | imaginary line around the earth that divides the earth into 2 parts; parallel halfway between the North and South poles. |
| prime meridian | median that runs though Greenwich, England, at 0 degree longitude. |
| international date line | imaginary line along the 180th meridian at which the date is adjusted |
| summer solstice | when the Northern Hemisphere has its longest day |
| winter solstice | when the Northern Hemisphere has its shortest day |
| umbra | a small, completely dark, inner area of a shadow |
