Satellites can easily detect what is not visible to the human eye. NASA's Aqua satellite acquired imagery of a large wildfire burning in Western Quebec on 19 June 2013, near the shoreline of Hudson Bay.
Water isn't the only thing pouring over Niagara Falls. Pollution from fires in Ontario, Canada is also making the one thousand mile trip, while being measured by NASA's Aqua satellite. One instrument that flies aboard two of NASA's satellites has provided two views of the pollution from the fires in Ontario.