Question: Humans get naturally fatigued after approximately 24 hours without sleep. If we lived on a planet wirth a day that was longer, would we adapt and be able to stay awake for longer?

Monique Henson answered on 12 Nov 2015:

That’s still something we’re a bit unsure about! It could be a bit of problem if we’re planning to spend prolonged periods of time in space. People are currently researching this by looking at shift workers – people who work night shifts for example. I think (although I don’t have a reference for this) there’s evidence that night workers tend to get more health problems, which may suggest that trying to live on different sleep cycles can have severe problems.