At the center of our solar system lies a variable magnetic star. It warms all the planets and provides the light energy necessary to support life on Earth. However, the sun is also subject to sudden explosive outbursts, called solar flares, which give off intense fluxes of radiation and highly energetic charged particles. The Earth's atmosphere and magnetic field provide a natural shield against much of this radiation. However, other types of solar eruptions, such as coronal mass ejections, energize the earth’s magnetic field and cause magnetic storms that produce the aurora borealis. These and other forms of "space weather" had little impact on human society until the invention of the telegraph, radio communications and the rise of large scale electric transmission grids – all of which can be disrupted by severe forms of space weather. Today we rely on telecommunications, direct broadcast television and radio, GPS and a host of other space-based infrastructure that can be degraded or in extreme cases disabled by space storms. In this talk we will describe the most important types of space weather, NASA's efforts to better understand the science behind them, and possible approaches to forecasting and mitigation.