From what I have heard, that is nothing.
Actually, I really can't say much, because much isn't known. All that I know is this: its called Aurora, and its supposed to be fast. And weird jet trails have been seen over Nevada Air Space for a few years now.
I've heard about hyper-sonic planes using some kind of "deflection" technology to get around the heat buildup associated with high-speed travel.
PS...the "deflection" technology is the reason for the weird jet trails that have been reported.
I'd say more, but "they" are listening.
Ramjets leave a trace much like a smoke ring...
twixt a short stream. PUFF BAM PUFF BAM. I've
seen them for some time in NV. Scrams are
all BAM. No contrail at all. Too efficient.
And the tests have been too high for such to
be manifest. BAM and gone. Delete my saying
I'm just pleased to see that you're linking to such an excellent, enlightened paper, one with the most perceptive and discerning of all editors, especially that Sunday Outlook section.