DevotedSkeptic writes with an interesting article on possible lighting sources for growing food on the moon and other off-world locations. From the article: "... Agriculture remains the key to living and working off-world. All the mineral ore in the solar system can't replace the fact that for extended periods on the Moon or Mars, future off-worlders will need bio-regenerative systems in order to prosper. Here on earth, researchers still debate how best to make those possible, but nuclear-powered state of the art LED technology is arguably what will drive photosynthesis so necessary to provide both food and oxygen for future lunar colonists. ... Although during the two weeks that make up the long lunar day astronauts might be able to funnel refracted sunlight into covered greenhouses or subsurface lava tunnels, they will be left without a light source during the long lunar night. Current solar-powered battery storage technology isn't adequate to sustain artificial light sources for two weeks at the time. Thus, the most practical solution is simply to use some sort of Radioisotope Thermoelectric Generator, not unlike the one powering the current Mars Science lab, to power the LEDs that will spur photosynthesis in lunar greenhouses. ... On earth, Mitchell says it takes roughly 50 square meters of agriculture to provide both food and oxygen life to support one human. But, as he points out, who can say how productive plants are ultimately going to be on the moon, in gravity that is only one sixth that of earth?"