“The human eyes and brain have mechanisms for self-adjustment in entirely new environments, such as other planets, regarding both color and intensity.
NASA’s Curiosity rover takes a selfie on Mars. Photo: NASA/JPL-Caltech
The human brain is adept at adapting to different lighting conditions. For instance, when wearing colored sunglasses, initially, the wearer perceives the color vividly, but after a while, the colors start to appear ‘normal’ again. This also occurs naturally as people age. The lenses of an older person’s eyes tend to yellow over time. However, they don’t see colors in that way because the brain compensates for the difference.
So, how would the brain adjust to colors in an entirely new environment, like other planets? Experts weigh in on what colors might look like on different planets.
Similar mechanisms might come into play when astronauts visit another planet. According to research by Michael Webster, a perceptual vision scientist at the University of Nevada, the mechanisms that adjust for yellowing lenses and colored sunglasses may also come into play when astronauts visit another planet. Depending on the dominant colors in the new environment, the astronauts’ brains would adjust to perceive them in a more neutral way.
“My prediction is that when people go to Mars, it’s not going to look red to them over time,” Webster said. Instead, the Martian landscape may start to look more brown or gray, and the Martian sky, while not blue like Earth’s, may appear significantly less orange than what humans see now.
However, not all extraterrestrial skies will appear greener over time. This depends on the dominant color of the light that passes through the atmosphere compared to the dominant colors of the landscape. In contrast to the orange within the color wheel (or color circle) is blue, so cooler tones may stand out more as the astronaut’s brain shifts toward neutrality. But if astronauts were to visit a planet with a purple vegetation carpet and a yellow sky, their brains might adjust differently.
The ‘filter’ of human perception doesn’t just limit itself to colors; it also adjusts to intensity. On a planet with a limited natural color palette, the brain would harmonize with subtle changes in hue. Over time, astronauts might find faint colors becoming more vibrant, and vice versa.
What if, instead of waiting for astronauts’ eyes and brains to adapt to the new planet, humans invent an automatic filter device for that environment? Derya Akkaynak, an engineer and marine scientist at the University of Haifa, and her colleagues are researching a similar concept, although their research is being conducted in underwater environments rather than space.
In theory, if you know the composition of the atmosphere and ocean of an alien planet, you could predict how light would interact with that place. Then, experts could use this information to create an algorithmic filter, which would help ‘correct’ the colors of the environment. This filter could be integrated into the faceplate of space suits.
Before humans actually visit another planet, it’s impossible to know exactly how the process of adjusting to the extraterrestrial color palette will work. However, deep-sea research may offer a close approximation. Akkaynak once dived 30 meters underwater, deep enough to filter out red light. ‘Everything looked yellow instead of blue, probably because I was compensating for the lack of red. But overall, the scene looked really bizarre,’ Akkaynak said.