It’s been 40 years sinceOlivia Newton-John, 69, andJohn Travolta, 64, joined forces to play good girl Sandy and bad boy Danny in 1978’sGrease. Together they made movie history (the film earned almost $400 million worldwide) and also launched a friendship that has lasted four decades.
“We did something life-changing, making that film,” Newton-John tells PEOPLE. “[At the premiere] you got the feeling from the energy that something was happening. It was a huge response. I feel grateful to be a part of that and to have worked with him. We’ve stayed friends ever since.”

To mark the occasion, Paramount recently released a40th anniversary DVD editionofGrease,which includes a fully restored version of the film and bonus features.
“[In tough times] John always reaches out to me,” she says. Travolta echoes the sentiment.
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“When you share that kind of meteoric success—and nothing has been able to exceed it—you share a bond,” he says. “I’ve been through her having a child, getting divorced, losing her sister. She’s been through my getting married, having children. It’s wonderful and full of shared memories.”
For more on Travolta and Newton-John, pick up this week’s issue of PEOPLE on stands Friday and PEOPLE’s 40th Anniversary Grease special issue July 6.
And while the duo both passed onGrease 2, they costarred again inTwo of a Kindin 1983, which unfortunately bombed. “You never know with films,” says Newton-John. Then in 2012, they released the albumThis Christmas, benefiting her Olivia Newton-John Cancer Wellness & Research Centre and his Jett Travolta Foundation for children with special needs.
Even with Newton-John living in Australia, she says the two continue to keep in touch and often text.
“Olivia’s quite a spectacular human being,” adds Travolta. “She’s worthy of good friendship.”
source: people.com