The experience was equal parts incredible and terrifying.

In 2021, actor William Shatner joined the crew of the Blue Origin civilian vessel for a brief trip to the boundaries of space. Shatner was excited for the opportunity, having built most of his career as the spacefaring Captain James T. Kirk on Star Trek. However, while the voyage to the final frontier was incredible, the sight of the infinite expanse brought about something else in Shatner: a feeling of profound sadness.

“All I saw was death." Actor William Shatner, who joined a suborbital space tourism flight last year, had a very distinct observation when he turned his gaze from the Earth to black expanse of the cosmoshttps://t.co/q1SoGOqGyY

— CNN (@CNN) October 10, 2022

“I saw a cold, dark, black emptiness. 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,” Shatner wrote in his new book, “Boldly Go.”

“Everything I had thought was wrong,” Shatner wrote. “Everything I had expected to see was wrong.”

William Shatner expected that going to space in October 2021 would induce “the ultimate catharsis.”

Touching the ground, Shatner wept, and he wasn’t sure why. It took him hours to realize what he was experiencing: “great grief … for the planet.” https://t.co/4WFtUndJ7q

— The Washington Post (@washingtonpost) October 10, 2022

The relative smallness of the Earth in the midst of a vast, empty void made Shatner keenly aware of just how fragile our planet actually is. “When I stepped out of the spacecraft, I started crying. I didn’t know why,” Shatner explained in an interview with CNN. “It took me hours to understand why I was weeping. I realized I was in grief for the Earth.”