Pat Flannery wrote in news:5_SdnYVvlbQdK-
hdakotatelephone:

Pat Flannery wrote:
Really interesting photo and story about shockwaves from the recent
Atlas V launch hitting a thin cloud layer under it as it ascends:
http://www.armscontrolwonk.com/2636/shocking-good-fun

Scott Lowther found a great video of this on YouTube; the waves start at
the 1:52 point.

One explanation is the low-frequency acoustics of the RD-180; really
ripples the ice crystals in the cirrus layers, with additional
effects from the expanding exhaust backwash.

I'm surprised this has not been observed before; it's spectacular!

--Damon "I'm sorry. My (rocket)car ran over your (sun)dog."