World on a Window Sill, Part 2

When you read World on a Window Sill, Part 1, you learned about globes. Now you will learn more about latitude and longitude. Why are they important, you ask? Well, latitude and longitude lines form a grid system. A grid system is a group of horizontal (east to west) and vertical (north to south) lines. These lines intersect or cross at coordinates. Coordinates are the points where the lines meet. Latitude and longitude help you to locate places on maps and globes. Remember, you won't see these lines on Earth. They are imaginary lines.

An atlas is a book that has many different maps. It may include physical maps and political maps. Physical maps show an area's physical features or landforms. Political maps show boundaries of and locations of countries, states, capitals, and cities. You may also see thematic maps. These are maps that show details about special topics. There may be maps that show climate differences in the U.S. You might see population maps of different countries.

Let's return to the globe. As a three-dimensional model, it is shaped like a sphere. Therefore, any way you travel around the Earth, you will be going in a circle. A circle has 360 degrees. That is why a globe has 360 degrees. Using the equator as our starting point, we can figure out the degrees of our poles.