What makes scientists so confident that we're going to survive in the Mars, let alone spend a week in the moon? Lettuce. And growing them underground in the moon or on Mars.

In reality, scientists are more challenged by the prospect of growing real subsistence food than bringing humans into space. In fact, finding a way for plants to grow in these low atmospheric pressure, carbon-free environments is the single most important breakthrough that will ever be discovered by humans in this generation.

At the Texas Agricultural Experiment Station, researchers have grown lush, large-headed lettuce inside growth chambers that mimic the atmosphere of the moon and Mars. They've just discovered that it was actually possible for the plants to grow, even in low pressure and darkness.

Ethylene, a chemical compound widely used in the stimulation of plant growth and ripening, plays an important role in this experiment. Plants churn out less ethylene and absorb less carbs at night, saving the scientists less material to grow plants, but resulting in better lettuce produce.

Does this signal the end of reconstituted food in toothpaste tubes for our astronauts? Maybe, but growing plants elsewhere in space is also a boon to humans in many ways other than giving us nourishment. It's too early to say anything, but the findings give us hope that outer space explorations will continue. For the astronauts, at least. But humans subsisting on real, Earth food in the moon is, well, something only the lettuce inside the growth chamber can tell.