7 ms·Contrails condense from water vapor, but are not themselves water vapor.by pfdietz 1y agoContrails condense from water vapor, but are not themselves water vapor.alliao 1y agodoes it have some kind of nuclei and have water vapour surround it? I'm guessing from impurities of burnt fuel?pfdietz 1y agoParticles in the exhaust from incomplete combustion, I think.