On March 9, 2008, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite detected hundreds of fires burning in West Africa. Places where the sensor detected active fires are marked in red. Northern Hemisphere winter and early spring are the dry season in this part of the continent, and people set fire to cropland and pasture on a large scale to prepare for the upcoming growing season. At the time of this image, fire activity was especially intense in southeastern Guinea and northern Liberia. Although it is not necessarily immediately hazardous, such large-scale burning can have a strong impact on weather, climate, human health, and natural resources.