Its the change in air pressure causing the moisture to condense I believe.
“Its the change in air pressure causing the moisture to condense I believe”.
Absolutely correct. And, the sound barrier doesn’t need to be broken for the phenomena to display itsself. The cool cone pattern is often seen at low altitudes along coastal areas, where the change in pressure does not require very high speed.
Since 1972, supersonic speed over the contintal US has been illegal. Althought the FAA has no jurisdiction over military operations, in this case the DOD compys except over certain MOA’s and segments of training routes.