In psychology, there's a rare term called the overview effect, where astronauts may feel fear when looking back at Earth from space.

When astronauts gaze back at Earth from space, they are affected by a rare psychological phenomenon known as the overview effect.

This effect is rare because it can only be triggered when one leaves Earth. In essence, when individuals as independent beings reach beyond Earth, seeing the entire planet for the first time, they experience a tremendous sense of unfamiliarity and detachment.

It's as if they are isolated from the entire universe, and the boundless blackness of space only intensifies their feelings of fear.

Describing her experience of extravehicular activity, China's first female astronaut, Liu Yang, stated:

As she stepped out of the airlock into space, she was surrounded by an exceptionally dark, "bottomless darkness," a depth so profound that words like "bottomless abyss" couldn't do it justice.

Confronted with this sight, Liu Yang felt a massive psychological impact, hesitating to continue staring into this abyss for fear of drifting away if she let go.

In 2016, a research team from the University of Pennsylvania in the United States analyzed the statements of hundreds of astronauts, with startling results:

The majority of astronauts experience unprecedented and overwhelming negative emotions when overlooking Earth from space.

One astronaut, who chose to remain anonymous, even expressed a belief that humanity would self-destruct within 500 to 1000 years while gazing at the tiny Earth amidst the vastness of the cosmos.

Today, the psychological experience of the overview effect is not limited to astronauts, as many billionaires have embarked on space travel, witnessing Earth from beyond its boundaries.

For example, upon reflection, Hailey Arsenault wrote that during her time in space, seeing all countries simultaneously for the first time evoked an even stronger sense of inequality, making her realize the ugliness beneath the surface of Earth and the vast disparities in living conditions among people in different regions.

However, these individuals are still confined to near-Earth orbit.

Historically, the astronauts of the Apollo program who walked on the moon were most profoundly affected by the overview effect.

As they gazed at Earth from the moon, they saw a massive Earth hanging in the dark void of space. The combination of the overview effect and the fear of large objects greatly impacted the psyches of many moonwalking astronauts.

Armstrong's companion, the second astronaut to set foot on the moon, Collins, deeply realized upon returning to Earth that humanity is insignificant on the cosmic scale.

Across the 238,000 kilometers of distance, human quarrels and clamor became insignificant, replaced by the sadness of a fragile civilization dwelling on a fragile planet.

In the words of Carl Sagan: "The Earth is just a mote of dust in a sunbeam."

As space travel becomes increasingly commonplace, more and more people will be able to witness Earth from space, triggering their own overview effect.

However, as more people experience this phenomenon, the collective consciousness of human civilization will reach a new level.

Perhaps in the not-too-distant future, more people will realize that humanity should explore the universe as a whole rather than remain fixated on the gains and losses of Earth.