Last night we started seeing a weird looking radar image coming out of Caribou. Today we briefly chatted with the National Weather Service in Caribou about what it was. It's military chaff. 

Some military planes have the ability to release a metallic substance that is used to trick radar guided missiles into thinking the planes are somewhere else.  

Military chaff shows up often enough in Northern Maine that the NWS in Caribou is used to the signature shown on the radar.