NASA - National Aeronautics and Space Administration

Air is arguably the closest and most important biological connection we have with the rest of the world. We breathe air into our bodies every few seconds. Like it or not, we share the air we breathe with the people around us, whether friends or strangers.

"Yuck!" you may say. But it's how our world is constructed. As a species, we have developed to live this way. One atmospheric chemist pointed out, "Air may not look like much, but try breathing something else."

We share the air we breathe not only with other people but also with the rest of our environment -- automobiles, airplanes, factories, plants, animals, lakes, oceans -- you name it. Air moves as wind from one place to another. The air we breathe and the stuff that's in it have come from somewhere else.

Moving air carries a wide range of substances, including moisture, dust, bacteria and viruses. Air also contains trace gases such as ozone, nitrogen oxides and sulfuric acid. It stands to reason that we need to know where our air comes from and what happens to it before it gets to us.

Image to left: Smoke and air pollution, such as that seen over eastern China by NASA's Moderate Resolution Imaging Spectroradiometer (MODIS), can travel and affect air around the world. Credit: NASA

Do you know where your air has been? NASA wants to know. Scientists working with data from NASA's Earth-observing satellites have discovered, to their surprise, that air pollution is an intercontinental traveler.

Dust from the Sahara Desert has turned up on coral reefs in Florida. Air pollution from the northeastern United States sometimes reaches Europe. Smoke from Asian fires crosses the Pacific Ocean all the way to southern California. And in 1997, sea salt and frozen plankton picked up by Hurricane Nora in the Pacific made it to the Midwest.

Image to right: NASA's Aura satellite launched in July. Credit: NASA

The point is that many areas will not have clean air until others do.

NASA launched a new satellite named Aura in July. Aura has already begun to map ozone and the chemicals that react to produce it. These are exciting times for atmospheric chemistry!

Adapted with permission: ChemMatters magazine © American Chemical Society 2003
http://www.chemistry.org/education/chemmatters.html

Related Resources

Aura
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NASAexplores: The Air That We Breathe
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Jeannie Allen
NASA Goddard Space Flight Center