The other one is from 2017, isn’t active and has no votes.
Engine Condensation, if not is one of the most gorgeous things to see on a plane, whether its on Takeoff or Landing.
This youtube Comment Explains it more in depth.
It’s called Bernoulli’s principle. the velocity of the air entering the engine is increased. if you increase velocity, you decrease pressure. when you decrease pressure you also decrease temperature. the temperature of the air is lowered to the dew point, ergo visible moisture. as stated it is more pronounced on humid days when the temperature dew point spread is very close (only a few degrees).
It looks absolutely beautiful and would definitely make good screenshots when the weather is foggy in some places.