We are all familiar with NASA's long string of triumphs in spaceflight and the exploration of distant worlds and the cosmos. No less impressive is NASA's record of achievements in helping us understand our home planet.

Since the beginning of the space age, NASA has been at the forefront of using Earth orbit to get a better view of how weather systems develop. And now the world is a safer place to live when it comes to dangerous weather.

NASA satellites and aircraft provided critical evidence in the international diagnosis of Earth's ozone layer. With scientific proof of how certain man-made chemicals were destroying the protective ozone layer high in the stratosphere, the nations of the world acted to ban the culprits.

In the 1970s, the U.S. Geological Survey and NASA developed a satellite instrument that could pick out different types of large-scale agricultural crops and map their location. Scientists used this tool to estimate the size of annual yields of wheat, corn, soybeans, and other crops.

NASA began keeping an eye on the temperature of the world's ocean surface in the 1970s. Without the continuous record of sea surface temperature, scientists would not have a key piece of evidence for global warming.

Scientists had only a fuzzy picture of the world's changing oceans before NASA joined forces with the French Space Agency to measure the height of the sea surface from space. The view from space revealed a dynamic ocean that shapes our climate and a rise in sea level three times faster than a century ago.

Air pollution was once thought of as just a local problem. But global views from space by NASA and other space agencies confirmed that pollution can move from country to country and even across oceans. In the 1980s, the first maps of ozone pollution low in the atmosphere drew attention to human impact on the atmosphere.