Great shot! I never was a fan of the Hornet, but who can resist a great a photo of a cat launch when the jet is at full burners?
Water molecule's in the air are compressed and separated by the fast moving object (in this case an F/A-18) into vapor. So litterally that jet is moving so fast and creating so much friction it's squeezing the water right out of the air. Freakin' sweet.