John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
The strongest daytime meteor shower of the year is producing glassy radar echoes.
You might not know it from looking at the sky, but there’s a meteor shower reaching its peak today. Hundreds of space rocks are whizzing through the atmosphere, but the timing is such that sunlight obscures their fiery demise.
While you might not be able to see the Arietid meteors (unless you rise in the dark before dawn), you can still surveil them with your ears. That’s because the year’s most active daytime shower produces distinct, whining radar echoes. Head to Spaceweather Radio for a listen; you’ll know you caught one when you hear what sounds like a person rubbing a finger around a wine glass. (Here’s an example from a Geminids shower.)
This particular broadcast is run by radio engineer Stan Nelson in Roswell, New Mexico. Here’s more about what you’re eavesdropping on from NASA:
Arietid... meteoroids strike Earth’s atmosphere at about 75,000 mph. As they move rapidly through the air, these specks of space dust heat and ionize the gas around them. During major meteor showers like the Arietids and zeta Perseids, radio signals from TV stations, RADAR facilities, and AM/FM transmitters are constantly bouncing off these short-lived meteor trails. Whenever a meteor passes overhead with the correct geometry, radio listeners can hear a brief “blip” (the reflected signal of the distant transmitter) on the receiver’s loudspeaker.