How to Grow Better Space Lettuce

NASA is funding research on a technique that could increase the yields of extraterrestrial crops

- By Larissa Zimberoff

Lush romaine lettuce grown beneath orange-hued QD film

The key to better eating on Mars might be a technology whose main commercial use today is enhancing the colors on television screens.

Quantum dots, or QDs, are tiny human-made particles whose properties can be manipulated so they emit specific colors when exposed to light. In consumer electronics, this proves useful for making brighter, more energy-efficient screens. In agricultural settings, quantum dots can be integrated into films that convert sunlight to orange and red light, colors that boost plants’ photosynthetic efficiency.

Directing the light from high-intensity lamps through a film coated in quantum dots increased leaf size and yield in romaine lettuce by 13% in a recent study published in the journal Communications Biology. (The type of romaine the researchers used is called “Outredgous.”) Such films could significantly improve the prospects of extraterrestrial crops, by converting the ultraviolet radiation common in space into light that’s nourishing to Earth plants. It puts a new spin on the long-standing assumption that the way to higher yields is more light. Now growers can turn the light they already have into something better.