On mars for every square meter of greenhouse you would need 0.423 square meters of sunlight concentrators. These parabolic dishes or troughs could focus light into a light pipe that channelled it through the shielded wall of the greenhouse, through filters, and distributed it within. The alternative would be large windows, but this wouldn't be practical since the greenhouse would have to be pressurized against the near-vaccum of Mars' atmosphere. They also wouldn't protect well against micrometeorites, and cosmic rays.
Agriculture in space has got to be one of the grand challenges, don't you think? Unless we evolve into something else, but that will take a rather long time. Possibly longer than building a space-faring community.
Space/Science » in reply to I think that was Success_Machine. nt
Re: Light-pipes for Mars Agriculture