had some observations following his trip to outer space, and they weren’t very positive due to his concerns about .

The 91-year-old Canadian reflected on a space tourism trip he took last year as part of his new memoir, “Boldly Go: Reflections on a Life of Awe and Wonder.” While other space travelers usually say positive things about the trip, the “Star Trek” alum recalls feelings of grief.

“Stars exploding years ago, their light traveling to us years later; black holes absorbing energy; satellites showing us entire galaxies in areas thought to be devoid of matter entirely… all of that has thrilled me for years…,” the passage begins, per .  “But when I looked in the opposite direction, into space, there was no mystery, no majestic awe to behold… all I saw was death.”

“I saw a cold, dark, black emptiness,” Shatner continued. “It was unlike any blackness you can see or feel on Earth. It was deep, enveloping, all-encompassing. I turned back toward the light of home. I could see the curvature of Earth, the beige of the desert, the white of the clouds and the blue of the sky. It was life. Nurturing, sustaining, life. Mother Earth. Gaia. And I was leaving her,” the excerpt reads.

“Everything I had thought was wrong,” the passage continues. “Everything I had expected to see was wrong.”

The actor went on to describe how his negative feelings stemmed from his belief that humans are destroying the planet.

“It was among the strongest feelings of grief I have ever encountered,” he wrote. “The contrast between the vicious coldness of space and the warm nurturing of Earth below filled me with overwhelming sadness. Every day, we are confronted with the knowledge of further destruction of Earth at our hands: the extinction of animal species, of flora and fauna . . . things that took five billion years to evolve, and suddenly we will never see them again because of the interference of mankind.”

Despite expecting the journey to be thrilling, the actor recalled the trip as having a somber feeling. 

“It filled me with dread. My trip to space was supposed to be a celebration; instead, it felt like a funeral.”

Previously, Shatner had his book with CNN and said he’s a “verbal ecologist” who is adamant about getting the message out about man-made climate change.

“The possibilities of an apocalypse are so real. It’s hard to convince people — and especially certain political people — that this is not on our doorstep any longer. It’s in the house,” he told the publication at the time.