Wildfires can be sparked by a number of sources, including naturally via lightning strikes or simply by heat from the sun, but experts say most are caused by humans.

Many Earth-observing satellites can detect the heat signatures associated with wildfires. NOAA’s N-20 satellite passes over every spot on Earth at least twice a day and can detect fires with 375-meter accuracy.

Check out this wildfire app that displays hotspots and fire activity in real time in the US and Canada, and within 3 hours for the rest of the planet.