A unit is a unit right? Well....some units are...astronomical!! They are so big and ginormous that they are out of this world! (Hee, hee!) An Astronomical Unit is the distance between the Earth and the Sun. In 2012, the International Astronomical Union defined the distance to be 149,597,870,700 meters. (That's 149,597,870,700 meter sticks!) Tycho Brahe estimated the distance between the Sun and the Earth at 8 million kilometers (5 million miles). He wasn't even close. But he lived without calculators and a computer so I'm definitely willing to give him a break. It's really 93,000,000 miles. That is one astronomical unit! Remember this is an average number because the Earth's orbit is _________________Elliptical! You guessed it! Astronomers use the Earth’s average distance from the Sun as a standard yardstick for measuring distances in the Solar System. That is really cool, and we thought a yardstick was pretty long! When you ask the question, "How far is that?" concerning the Universe, scientists now have a consistent unit of measure to use. This unit of measure makes it handy to see how far away the planets are from the Earth or the Sun. Bottom line: Astronomers like to list the distances to objects within our solar system (planets, dwarf planets, asteroids, comets, spacecraft, etc.) in terms of the astronomical unit, or AU. It helps them paint a picture of what our Solar System and Universe may look like. If you are outside tonight and take a look at the moon, you may see this: Have a nice weekend, sweet dreams of gravity, planets and other celestial objects! See you Monday.
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Mrs. TaylorI love science! Everything about the world is interesting and never boring. I love to study plants, animals, insects, and people. My favorite subjects are my students who are the most unique organisms on the planet! Categories |