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HOW FAR AWAY IS ORION?
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The stars are not all at the same distance from us. The closer a star is to us, the brighter it will look to us. Also, stars come in all different sizes as well as brightnesses. Larger stars usually are brighter than smaller ones. How bright a star appears in the night sky depends on its size as well as how far away it is. The closest star is about 25,300,000,000,000 miles (39,900,000,000,000 kilometers) away, while other stars can be billions of times farther than that.
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All of the stars in Orion's Belt are different distances away from us. Distances in space are measured by light years. Like Betelgeuse, the red star in Orion is over 3 quadrillion, 60 trillion miles away. Rigel is 773 light years away, or 773 miles. These two stars are two of the fifteen brightest stars in the sky.
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Imagine how big these stars must be if we see them this large and bright from so many millions of miles away! It is a crazy thing to think about...but exciting too!
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This question makes us wonder...how can you measure distance in space? Well, on howstuffworks.com they tell us this:
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It turns out that measuring the distance to a star is an interesting problem! Astronomers have come up with two different techniques to estimate how far away any given star is.
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The first technique uses triangulation (a.k.a. parallax). The Earth's orbit around the sun has a diameter of about 186 million miles (300 million kilometers). By looking at a star one day and then looking at it again 6 months later, an astronomer can see a difference in the viewing angle for the star. With a little trigonometry, the different angles yield a distance. This technique works for stars within about 400 light years of earth! (thanks to www.howstuffworks.com)
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