Julianne Hough has met a lot of stars during her tenure on Dancing With the Stars [1], but even she couldn't handle meeting Olivia Newton-John. Hough is playing Sandy in Fox's upcoming live version of Grease [2], so meeting the woman who played her in the 1978 musical must have been pretty surreal. Newton-John turned up to help judge Dancing With the Stars [3] this week, a totally fitting challenge, since the theme was about iconic movie and music video dances. Take a look at all the pictures of Hough and Newton-John, and let's all hope the original Sandy gets a cameo in the reboot!