When a meteoroid enters the Earth's atmosphere it acquires heat due to the formation of a shock wave and creates a trail of ionised gas or plasma. The plasma reflects radar signals. 

"The LVST makes use of the 'back and forward scatter' of radio waves broadcast by the GRAVES radar transmitter which operates at 143.05 MHz and is located near Dijon in the South of France .  Please explore the data on the following pages which the Jodrell Plank Team hope to build upon over the coming years. Meteors have shaped our planet and created the opportunity for our mammal ancestors to exploit. Without the intervention of the Chicxulub Meteor, 66 million years ago, we would not have evolved and the dinosaurs would still be in charge"!  Jodrell Plank Community outreach coordinator – Karl Seguine