Jet trails stay in the sky all the day long with the right meteo conditions. They just become wider and look like long clouds. Check the picture at https://www.

Jet trails stay in the sky all the day long with the right meteo conditions. They just become wider and look like long clouds. Check the picture at https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/clouds/other-clouds/contrails https://www.metoffice.gov.uk/weather/learn-about/weather/typ... Also this paper https://www.mdpi.com/2226-4310/7/12/169 https://www.mdpi.com/2226-4310/7/12/169