Yes, it is. Do you know nothing about planes? The hot air from their exhaust fumes creates condensation at high altitudes (read as "in cooler air"), so the white stuff they leave behind is essentially condensed water vapor (clouds). It's basic atmospheric science.
That's not "exhaust" from jet engines.
Yes, it is. Do you know nothing about planes? The hot air from their exhaust fumes creates condensation at high altitudes (read as "in cooler air"), so the white stuff they leave behind is essentially condensed water vapor (clouds). It's basic atmospheric science.