If your summer travels have taken you across the Rocky Mountains, you've probably seen large swaths of reddish trees dotting otherwise green forests. While it may look like autumn has come early to the mountains, evergreen trees don't change color with the seasons. The red trees are dying, the result of attacks by mountain pine beetles.
Mountain pine beetles are native to western forests, and they have evolved with the trees they infest, such as lodgepole pine and whitebark pine trees. However, in the last decade, warmer temperatures have caused pine beetle numbers to skyrocket. Huge areas of red, dying forest now span from British Columbia through Colorado, and there's no sign the outbreak is slowing in many areas.
The affected regions are so large that NASA satellites, such as Landsat, can even detect areas of beetle-killed forest from space. Today, NASA has released a new video about how scientists can use Landsat satellite imagery to map these pine beetle outbreaks, and what impact the beetle damage might have on forest fire.