Can You Hear Them???!!!

Well, I've ventured into yet another realm of astronomy....radio astronomy. Specifically, using an FM radio to detect meteors. Huhhh???? Actually, it's a pretty simple concept. When you see a shooting star (meteor) many times you can see a brief tail behind it as it streaks across the sky. When the meteor enters Earth's atmosphere, it is going so fast, that it heats up the air around it, and the result is a tail of ionized gas. This ionized gas can reflect radio waves...specifically FM frequencies.

The trick is to find a radio station that is far enough away to be below my horizon (200-500 miles is ideal). Because the station's transmitter is shooting it's signal in a straight line, eventually, the signal continues into space. At my end, I just point the antenna in the direction of the transmitter and tilt it 45 degrees up. When a meteor passes between the station's transmitter and my receiver, the radio signal is reflected off the meteor's ionized tail and bounced back to the ground in my direction. In this photo, the antenna is pointed toward a Portland, Oregon FM station...101.9 KINK, about 180 miles south of me.

What I hear before a meteor is just white noise (static) from the station's frequency. When a "bounce" occurs, the station will briefly come in clear...maybe for only a second or two. I have a program that records audio to digital format. The program also shows a "wave" graph. This way, I can set up the program to record for any length of time, and I can go to bed. In the morning, I look at the graph and look for "peaks". These peaks indicate a boost in the radio signal. I then go to that point in the graph and listen to the static. If I then hear the station, I know I detected a meteor.

I know you are probably asking, "Why???"

Why not???