Test Bed -- brainstorming Weather Gods, or, a thrillah about the world's weather system and its manipulators in Friends and Foes A blog by william.scherk in General Posted September 5, 2019 21 hours ago, Jon Letendre said: Contrails are fine ice, not vapor. And they cannot persist more than about 90 seconds. What you see emitted from jets that persists for hours is a chemtrail. I am about 50. I had a telescope by age nine for watching the sun, moon, planets. I learned to identify over a dozen hawk species from thousands of feet, in the fourth grade. I watched the sky with great interest, on my back on the ground for hours per week my entire childhood. This was less than an hour from Boston so I saw planes at varying altitudes coming and going. I saw terminal height flyover traffic between Europe and New York/Chicago. Never, not once did I see a contrail persist longer than two minutes, and that was a very, rare event. A one minute contrail always got my attention. Even thirty seconds was a “long contrails” day. Note: The above is for any interested reader, and do know I would like to hear what you have seen in the skies over the years. Bob I am not so much interested in hearing from. Bob puffs his chest, slings insults and nerdy bigbrain put downs, then disappears when he is shown to be 110% wrong. I find it dishonorable in the extreme. See Where Are You thread as example. Bob can keep it intellectual, and then walking away is at least honest. Or he can do his usual walk in like a god, and then walking away without plainly acknowledging error is an order of magnitude worse than simple dishonesty. I don’t like being near it. Bullshit. Cirrus clouds persist for hours on end. The water trail from a jet is made of the same stuff as Cirrus Clouds. H2O in a solid state which occurs shortly after gaseous H2O condenses into liquid H2O. All the nasty gasses are invisible. SO2, NOx CO2.