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Q & A: The sky is falling! The sky is falling!

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Most recent answer: 10/22/2007
what is sky made of?will the sky drop down?
- anug
Anug -

First question first. Another word for the sky is the Earth's atmosphere. The atmosphere is made up of air, which is composed of a number of different gases, the most important of which (at least to us) are nitrogen (78%), oxygen (21%), and carbon dioxide (0.033%). There's also argon (0.93%), neon (0.0018%), and smaller amounts of helium, krypton, xenon, hydrogen, methane, etc. (From the .) Up high in the atmosphere, just before you reach open space, there's also a layer that contains a lot of ozone (the "ozone layer"), followed by a layer containing a lot of miscellaneous ions (the "ionosphere").

As for the second question, the sky sure will drop down! At least it will continue to do so, since it already has. And it's a fortunate thing, too. If the atmosphere wasn't held down near the ground by gravity, the air would just spread out through space and we'd have nothing to breathe. Gravity holds the atmosphere against the Earth, but the air is light enough and has enough energy of its own that it doesn't get compressed all the way against the ground under our feet.


(published on 10/22/2007)

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