cosmictraveler":1mo7m363 said:
Couerl":1mo7m363 said:
Looks commercial, climbing and coming out of LAX I would guess.
I'd agree. It looks rather strange because of the angle it was taken at. But its just a contrail of a jet like you say, taking off.
Any jet big enough to be trans-pacific (even just to Alaska, along the western coast) isn't going to leave a single huge cross-section contrail right from the source. The camera angle is bad, and the contrail source is separating from the camera, but I didn't see any evidence of individual engine contrails merging, even from just a twin-jet aircraft. The apparent surface shape of the contrail close to the vehicle emitting it looked way too regular/simple/circular in cross section. It also looked to be way too dense optically to be a simple jet contail: those are essentially hot water vapour condensing (burn a gallon of hydrocarbon, get heat/thrust - and a gallon of water). SRB smoke is visibly different, but it's not water vapour. Further (again, hard to see in this video), but there's usually a gap between the jet exhaust and the contrail formation - the water vapour has to cool through the local dew point to condense and become visible. SRB smoke exists from within the combustion chamber until it's diluted to invisibility in the atmosphere, a process way less dependent on air temperature.
I suppose it
might be an aircraft, but contrail-forming conditions don't normally localize to the point where all the other jet traffic in the vicinity doesn't leave contrails; this contrail extended several miles, seemingly over a range of altitudes (another difficulty for the jet contrail theory). LAX is a "bird cage" - where are all the other contrails? The other aircraft don't have to be climbing out of LAX - passing overhead would be sufficient for other contrails if this one was caused by an aircraft "just passing though" as well.
Is the apparent (angular) velocity consistent with an aircraft cruising at altitude? Climbing out? This would require some rigorous TMA to determine.