NM Fireball 01

On Saturday morning over Santa Fe a space rock, maybe tens of centimes across, hit the atmosphere at tens of kilometres per second, where its kinetic energy was released in a dazzling blast of light, and low frequency infrasonic sound waves.

You can see and hear this on a video made by an amateur astronomer, Thomas Ashcroft, and posted on Space Weather.

The sky and moon just before the fireball explodes
The sky and moon just before the fireball explodes

The meteor struck at a steep angle. The monochrome sky sentinel monitoring station first shows the pre-dawn moon in a dark cloudy sky, then the fireball briefly explodes into view, illuminating the entire sky and its clouds and buildings you can see on the outer rim of the circular whole sky image which has the 360 degree horizon as its circumference.

The static on the soundtrack comes from a forward scatter radar signal. Immediately after the fireball bursts into view the siren song of meteor is heard in the radar return, rather like a distant train horn.

Sometimes large fireballs like this can produce a strange acoustic effect in which people below them feel rather than hear a rasping sound at the top or back of the neck.

Papers about this effect, which is also attributed to some bright auroras, can be found using the terms electrophonic transduction, infrasound and infrasonic energy.

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