Oblique View of the Arnica Fire, Yellowstone National Park, Wyoming

The late summer/fall wildfire season is in full swing in the western United States. Significant wildfires are observed each year by astronauts orbiting the Earth on the International Space Station. This astronaut photograph documents the Arnica Fire in Yellowstone National Park. The fire was started by a lightning strike near Yellowstone Lake on September 13, 2009. By the time it was detected on September 23, 2009, it covered approximately 2 hectares (4 acres). The fire was photographed by the astronauts on the following day (September 24); by then, it had grown to 101 hectares (250 acres) in size. Warm, dry and windy conditions in the area provided a favorable environment for growth
of the fire, and as of October 1, 2009, the fire was estimated to be 3,764 hectares (9,300 acres) in size.