| A | B |
|---|
| Longitude | Angle that describes the distance east or west of the prime meridian |
| Continent | One of the seven major land areas of the Earth |
| Grid | Set of horizontal and vertical lines |
| Degree | Unit for measuring angles in a circle or sphere |
| Parallel | Line of latitude |
| South Pole | Point farthest south on the Earth |
| Meridian | Line of longitude |
| Hemisphere | Half of the Earth |
| Prime Meridian | Line of 0 degrees longitude |
| International date line | Imaginary line that defines the start of a day |
| Roatation | Spinning of the Earth or other object in space |
| Equator | Line of 0 degrees latitude halfway between the poles |
| Latitude | Angle that describes the distance north or south of the equator |
| Standard time zone | Area that has the same clock time |
| Axis | Imaginary line through the Earth that connects the North and South Poles |
| North pole | Point farthest north on the Earth |
| solar system | the sun and the nine planets and all other objects that revolve around the sun |
| planet | a spherical object that orbits around a star |
| satellite | a body that orbits a larger body |
| rotation | the act of turning around an axis; one complete spin of Earth on its axis, which takes 24 hours |
| revolution | the orbit of an object in spacel the orbit of Earth around the sun, which takes on Earth year |
| tropics | warm areas in the low latitudes |
| polar region | a cold area near the North or South pole |
| solstice | one of two times each year when Earth's polar axis points at its greatest angle toward or away from the sun |
| Tropic of Capricorn | the line of latitude, located at 23 1/2 degrees south of the equator, struck by the sun's most direcct rays of energy during the December solstice |
| Antarctic Circle | line of latitude located at 66 1/2 degress south of the equator; parallel beyond which no sunlight shines on the June solstice |
| Arctic Circle | line of latitude located at 66 1/2 degress north of the equator; the parallel beyond which no sunlight shines on teh December solstice |
| Tropic of Cancer | the line of latitude, located 23 1/3 degrees north of the equator, struck by the sun's most direct rays of energy during the June solstice |
| equinox | one of two times each year when Earth's polar axis is not pointed toward or away from the sun but is at 90 degree angle to the sun |
| Earth System | the interaction of elements on and around Earth |
| atmosphere | the layer of gases that surrounds our Earth |
| lithosphere | the solid surface of the planet that forms the continents and the ocean floor |
| hydrosphere | the physical system made up of all Earth's water |
| biosphere | the part of Earth in which all of the planet's plant and anima life exists |
