Years ago, most scientists believed that Earth was surrounded by an empty, unchanging vacuum. The launch of the first satellites in the 1950's changed all that. Now we know that space is filled with debris from disintegrated comets, an ever-changing million mile-per-hour solar wind, radiation belts and auroral fountains. Solar flares and coronal mass ejections can lead to poor radio communications or disrupted power grids here on Earth. Potential hazards to astronauts or satellites in space can be even more serious.

Space weather is a relatively new field of science dedicated to the study of these interactions between the Sun and the Earth. Practitioners of space weather attempt to predict solar flares, coronal mass ejections, geomagnetic storms and other space-related phenomena.

The official U.S. government bureau for space weather forecasting is the Space Environment Center (SEC). The SEC provides real-time monitoring of solar and geophysical events, conducts research in solar-terrestrial physics, and develops techniques for forecasting solar and geophysical disturbances. SEC's parent organization is the National Oceanic and Atmospheric Administration (NOAA).