Future Mars astronauts will have plenty to contend with if they are ever to make it to the Red Planet. In perhaps one of the most well-known experiments to simulate a trip to the planet, Mars500 had six men spend 520 days in a pressurized facility in Russia – the longest simulated space mission to date. The purpose was to test how well the men could cope with extended periods of isolation and confinement. The findings: After 18 months, the crew's chronic stress resulted in decreased brain activity.
Apart from confinement, astronauts also have physiological phenomena to cope with. One of those quirks of space life: Seeing strange flashes of light, even with one's eyes tightly shut. This is due to cosmic rays zipping through the astronaut's eyeballs and messing with their optic nerve, making them think they are seeing bright, luminous spots where they don't exist. As NASA astronaut Don Pettit wrote on his blog: “In the dark confines of my sleep station, with the droopy eyelids of pending sleep, I see the flashing fairies. As I drift off, I wonder how many can dance on the head of an orbital pin.”
For more brain-bending information, watch the video below by Physics Girl on BrainCraft.