Justin Long Shares A Rare Alan Rickman Photo From Behind The Scenes Of Filming

As "Galaxy Quest" celebrates its 25th anniversary, Justin Long is looking back with heartfelt gratitude—not just for the film itself, but for the remarkable people he shared the experience with, including the late Alan Rickman.

Long made his big-screen debut in the 1999 sci-fi comedy, starring alongside Tim Allen, Sigourney Weaver, Tony Shalhoub, Sam Rockwell, and Rickman. The film, a loving parody of "Star Trek" fandom, follows the cast of a cult sci-fi TV series as they’re unexpectedly thrust into an actual intergalactic crisis by aliens who believe their show was real.

On Wednesday, December 25, Justin Long marked the milestone anniversary by sharing a pair of nostalgic throwback photos from the set.

One touching image featured Long alongside Rickman, who passed away in 2016 at the age of 69, and their co-star Jeremy Howard.

"It was my first time on a movie set, my first time in LA, one of my first plane rides, and my first time meeting Sam Rockwell," Long shared with his followers. "This photo of me, Alan Rickman, and Jeremy Howard (who played my friend in the movie and could blow sh-t up with his mind in 'Accepted') was taken at a party that Alan threw for everyone in the cast and crew."

Long hadn't met Rickman before the party, though he "formed an idea" of who the actor "might be based solely on the incredible performances I’d seen him give as villains in movies like 'Die Hard' and 'Robin Hood.'"

"My experience with him as a person was the exact opposite of that…he was so kind, generous, and yes, dry (VERY dry) but in such a playful spirited way," Long admitted. "I think about him often and when I look back on that experience a quarter century later, one of the greatest gifts that came from it was getting to know and work with an actor like Alan. And Sam. I now know how rare they are."

Later in the caption, he thanked Jeremy Howard for sending the BTS photo of "one of the all-time greatest actors (and people) kindly obliging two giddy young actors who were just embarking on a fun and wildly fulfilling 25-year adventure."

He then gave a shout-out to all of the fans "for helping it last as long as it has."

"And, as always, to @bonnieezane for sending my tape to your sister, Debra, who ended up casting me in the movie," he concluded.

While reflecting on the film during an episode of the "Happy Sad Confused" podcast with Sam Rockwell, Justin Long shared his thoughts on the possibility of a sequel.

"There were drafts of [a TV series] that was gonna be done at Amazon before Alan passed," he said. "They were all ready to do that and Alan was gonna have to miss the pilot episode. But then he felt like he'd be better for the second episode. So that's how close that came."

The late Alan Rickman remains one of the most iconic and versatile actors in modern cinema and theater. Known for his deep, resonant voice and ability to portray both heroes and villains with equal mastery, Rickman carved out a legacy that continues to captivate audiences worldwide. From Hollywood blockbusters to the theatrical stage, his work demonstrated an unparalleled commitment to his craft and a rare depth of talent.

In 1988, Rickman made his Hollywood debut as the unforgettable villain Hans Gruber in "Die Hard" opposite Bruce Willis. Despite it being his first major film role, Rickman delivered a career-defining performance, blending wit, charm, and menace to create one of cinema’s most iconic antagonists. He became a household name once again with his portrayal of Professor Severus Snape in the "Harry Potter" series.

Over the course of his career, Rickman received numerous accolades, including a BAFTA Award, a Golden Globe, an Emmy Award, and a Screen Actors Guild Award.

On January 14, 2016, Alan Rickman passed away at the age of 69 after a private battle with pancreatic cancer. His death came as a shock to fans and colleagues alike, with tributes pouring in from around the world.

Rickman’s final performances in "Eye in the Sky" and "Alice Through the Looking Glass" were released posthumously, leaving fans with one last glimpse of his brilliance.