Billy Simons.. age 8,  Salt Lake City. Utah

How fast does the world go round?

The round earth is doing a very fancy dance in the sky. It turns and travels in several different directions at the same time. This goes on every second day and night. We don’t notice it because we are so used to it.

The earth travels 600 million miles in its path around the sun each year. It travels this orbit at an average speed of 1821 miles a second. The sun and all the planets are also moving around the giant Galaxy. Everything we see in the sky is moving around in the great cartwheel of stars. Our Solar System is going around the Galaxy at about 170 miles a second.

Then. once in every 24 hours. the earth spins around like a top' it is as though there were a rod through the middle of the world from pole to pole. This imaginary line is the axis. Of course. it is not a real rod.

If you sliced the world in halt at the equator you could look down on a flat circle. It would be turning from the west to the east. much like a spinning top. Some spinning toys have circles painted on top, one inside the other. With each turn each circle turns around once.. But the outer circles are larger and have a greater distance to turn. so they must turn faster to keep pace with the smaller circles nearer the top.

So it is with the turning earth. The biggest circle is halfway between the two poles. This is the earth’s fat waist  the equator. That biggest circle must turn fast enough to keep up with the smaller and smaller circles nearer the poles.

These circles are as imaginary as the axis rod through the world. They are called latitudes. They are parallel circles running around the earth to help us divide it in sections. The equator is the biggest circle. The further from the equators the smaller each latitude circle becomes. The smaller the circles. the slower it spins around the earth’s axis.

The earth is about 24000 miles around the waistline. This means that the equator must spin around that distance every 24 hours. So, at‑the equator,  the earth goes around at about 19000 miles an hour. Now what about the smaller circles of latitude nearer the poles? Here the earth goes around more slowly.

In northern Greenland the earth goes around at about 90 miles an hour. The Gulf of Alaska is further south on a larger circle of latitude. Here on Latitude 60 North of the equator the earth turns at about 515 miles an hour. Goose Bay over in eastern Canada. is near Latitude 55 North. Here the earth goes around at almost 600 miles an hour. Ottawa  Canada. is near Latitude 45 degrees North. The circles are getting larger and faster„ Here the earth turns at about 795 miles an hour.

Philadelphia. Pennsylvania. is close to Latitude 40 degrees North of the equator. This beautiful city is turning from west to east at a speed of about 790 miles an hour though no one there notices it. Salt Lake City is just a few miles north of the same circle of latitude. so you are busy turning around at about 790 miles an hour.