Gray-blue smoke spreads across Southeast Asia in this Moderate Resolution Imaging Spectroradiometer (MODIS) image captured by the Aqua satellite on March 1, 2004. Scores of fires were detected by the sensor and have been marked in red in the image. Countries shown in the image are China (top), Vietnam (right edge), Laos (left of Vietnam), Thailand (bottom center), and Myanmar (top and bottom left).
The widespread nature of the fires and their location (generally located away from remaining natural vegetation, which appears deeper green) suggests that these fires are being set intentionally for agricultural purposes. Though not necessarily hazardous, such large-scale burning can have a strong impact on weather, climate, human health, and natural resources.
The high-resolution image provided above is 500 meters per pixel. The MODIS Rapid Response System provides this image at additional resolutions.