Imagine it's a cool October evening in 1957. You finish your dinner and walk outside your house.

You look up at the night sky like you've done hundreds of times before. The stars are twinkling

like they always do. Everything seems normal and peaceful, but then you notice something different.

A tiny dot of light is moving slowly across the stars. Your eyes follow it as it

glides silently overhead. Wait a minute. That's not normal. It's not a plane because it's too

high and too quiet. It's not a shooting star because it's moving too slowly and steadily.

Your mind races. What could it be? Then you remember hearing something

on the radio earlier today. The Soviet Union launched something into space, something

called Sputnik. Your heart starts beating faster. Could that be it? Are you really

watching a man-made object flying through space right now?

You stand there with your mouth open, unable to look away.

This tiny moving light above your head is something that has never existed before.

It's a satellite called Sputnik and it's orbiting Earth.

You're watching history happen right before your eyes and you know the world will never be the same.

On October 4, 1957, the Soviet Union launched Sputnik into space.

It was the first artificial satellite ever sent into orbit around Earth. Artificial means it was made by people, not by nature.

The word Sputnik is a Russian word that means traveling companion.

And that's exactly what it was.

It traveled around and around our planet,

circling the Earth every hour and 36 minutes.

Sputnik wasn't very big. It was about the size of a beach ball.

If you measured it across the middle, it would be 22 inches.

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