Essential Earth & Space Terms Defined

Understanding Key Earth and Space Concepts

Leap Year

A year with an additional day at the end of February, occurring every 4 years.

Orbit

The elliptical movement of the Earth around the Sun.

Cold Zones

Thermal zones where the Sun's rays strike the surface at a wide angle, resulting in low temperatures.

Temperate Zones

Thermal zones where the Sun's rays strike the surface at a moderate angle, resulting in mild temperatures.

Tropical Zones

Thermal zones where the Sun's rays strike the surface nearly perpendicularly, resulting in high temperatures.

Tilt

The inclination of the axis of rotation.

Cardinal Points

Basic reference points that allow us to find our location on Earth: North, South, East, and West.

Rotation

The movement of the Earth around its axis. Consequences include the change from day to night, the apparent movement of the Sun across the horizon, and the existence of hours.

Sunrise

The moment in which the Sun appears in the east, also called dawn.

Sunset

The moment in which the Sun disappears in the west, also called dusk.

Milky Way

The galaxy in which our Solar System is located.

Axis

An imaginary line that extends from the North to the South Pole of the Earth.

Scale

The relationship between a distance measured on a map and its corresponding distance on Earth.

Projection

A method that allows us to represent the Earth's spherical surface on a flat surface.

Map

A simplified representation of the Earth's spherical surface on a flat surface.

Parallels

Lines of latitude that are circles running perpendicular to the Earth's axis of rotation.

Latitude

The distance from any point on the Earth to the Equator.

Meridians

Lines of longitude that are semicircles running from one pole to the other.

Longitude

The distance from any point on the Earth to the Prime Meridian.

Geographical Coordinates

An imaginary grid made with two types of imaginary lines: parallels and meridians.

Hour

Each of the 24 equal parts into which a day is divided.