METEOR RADAR ECHOS: Have you ever wondered what a meteor echo sounds like? If so, play this movie --and turn up the volume!


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Giuseppe Petricca recorded this sound on June 27th from the Isle of Lewis, Scotland. "It was the echo of a meteor disintegrating over the GRAVES space surveillance radar in France," he explains.

Every day, 24/7, GRAVES scans the skies for satellites, meteors and other space debris passing over Europe. The radar sends a series of 143 MHz pulses straight up, and anything it "pings" is reflected far and wide. Petricca listens to the echos using a Yagi antenna and receiver tuned to the GRAVES frequency.

"This was one of the most intense meteors I have ever captured," says Petricca. "Doppler-shifting of the radar frequency allows me to measure the meteor's velocity: ~610 mph for the first part of the detection, decelerating to zero very quickly! This gives the reflection an 'L-shape' in the dynamic spectrum."

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