sundog 03

Amateur videos captured visible rings of rippling shock waves from a rocket launch in Florida last week, when of all things, the Solar Dynamics Observatory blasted past a ‘sundog’ caused by suspended ice particles in the air.

The effect was totally unexpected, as we can hear from the reactions of people also recorded on these videos.

While the NASA news story describes the rare, if not unique coincidence, it is not clear by how much the fierce acoustic energy emitted by a rocket engine added to the air blast of the Atlas V rocket as it tore through the sound barrier.

The noise energy from rocket engines is well above anything generated by the noisiest of aircraft engines.

There are many spectacular images in circulation of various types of shock waves generated by civil and military jets above and below the speed of sound, some of them unfortunately Photoshopped into images no human eye would have seen, but definitely not so in the example below.

[youtube]http://www.youtube.com/watch?v=QX04ySm4TTk&NR=1[/youtube]

In the videos made from viewpoints near Cape Canaveral, the shock waves are in one sense quite subtle, but remarkably regular in shape, and similar to the Catherine wheel effect seen over arctic Norway late last year when a Russian rocket test spun out of control, as shown below.

The Russian Catherine wheel rocket mishap last December.
The Russian Catherine wheel rocket mishap last December.

In the YouTubes below the shock waves occur just after mission control calls mach 1, the speed of sound, and the vision stays with the rocket as it encounters quite strong windshears in the stratosphere, which are visible in the twisting of the exhaust plume.

[youtube]http://www.youtube.com/watch?v=iwRfcrxFVEI&feature=youtube_gdata%20[/youtube] [youtube]http://www.youtube.com/watch?v=SsDEfu8s1Lw[/youtube]

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