Why does the Earth spin in the air without falling?

(Lansing State Journal, April 29, 1992)


Question submitted by:  Helen Sukis of Williamston Elementary School

Don’t be alarmed, but the Earth is continually falling.  The Earth is not falling in the same way a ball does when you drop it to the ground (that is in a straight line).  Instead, it falls in the form of an orbit around the sun.  To orbit means to circle around something.  A good example of orbiting is the satellites that orbit the Earth.

When we drop something on Earth it is the Earth’s gravity that pulls it down and the object falls in a straight line to Earth.

If we throw an object, it moves in an arc.  If we could throw an object hard enough (that is, give it a big enough velocity), it would circle, or orbit, the Earth.  A falling, object with a large enough velocity in the right direction can actually "miss" the ground and instead orbit.

In the same way that an object can "miss" the Earth, the Earth is pulled toward and misses the sun.

The Earth has a very big velocity away from the sun and so is pulled in an orbit around the sun that keeps it nearly the same distance at all times.

The Earth is being pulled toward the sun, but instead of falling into it, the Earth "misses" and orbits around it.

The time it takes the Earth to make one complete orbit around the sun is one year.


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