The Martian day is 40 Minutes longer than the Earth day. Working on a Mars Mission is like switching two timezones every three days.
Light is the strongest time cue, so the experiment used light to re-train the team’s body clocks.
In 2006, scientists recognized a new photoreceptor set in mammal eyes, which detects light at the blue end of the spectrum to help calculate time. …participants each got a box with 276 blue LEDs inside it, complete with a 20-inch piece of string so they knew how far away it should sit. They turned it on during their shifts—which may have happened in Earthly daylight or in the middle of the night, depending on the day.
“It’s like traveling three time zones west every two days. It essentially creates a jet lag,” Lockley explained.
The team members also got a crash course in how to crash properly—when to use caffeine and when to stop so it clears the system by bedtime; how to properly arrange a dark and comfy bedroom; and a “recognition that people are not superhuman,” Lockley said.
If team members were tired, they were supposed to report to a higher-up and find someone to help. The participants also had to give urine samples so the team could check for metabolites indicating the circadian rhythm, and wore wrist-mounted motion- and light-trackers to monitor their light exposure and sleep cycles.
…87 percent of [participants] synchronized to the Martian clock. They slept an average of six hours a night, but were less fatigued and more alert than those who didn’t synchronize to Mars.