The cast of 'Grease': This is what they look like now!

Since blasting onto our screens in 1978, watching Grease has become a rite of passage for every new generation of teenagers.

If you've ever wondered what happened to the cast of Grease, which turns an unbelievable 39 this year, here's your chance to get reacquainted with the T-Birds and the Pink Ladies of 2017...