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In the troposphere, ozone is pollution. In the stratosphere, we find the "good" ozone that protects life on earth from harmful rays from the Sun.
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Ozone - An Overview

Have you ever heard of ozone? That's a word that shows up in the news a lot! Do you know what ozone is and why it is important in the Earth's atmosphere?

Ozone is made of three oxygen atoms (O3). You've probably heard of oxygen before -- it's part of the air we breathe. The oxygen that we breathe is made up of two oxygen atoms (O2). Add another oxygen atom, and you have ozone! When a lot of ozone is around, you would see it as a pale blue gas. Ozone is found in two different layers of the atmosphere, the stratosphere and the troposphere. Where we find ozone in the atmosphere determines whether we consider it to be "good" or "bad"!

In the troposphere, the ground-level or "bad" ozone is an air pollutant that damages human health and plants. It is a key ingredient in smog. In the stratosphere, we find the "good" ozone that protects life on Earth from the harmful effects of the Sun. The simple saying "Good up high and bad near by" sums up ozone in the atmosphere.

Last modified January 8, 2007 by Jennifer Bergman.

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA