Astronauts may one day eat salad grown in asteroid soil.
Romaine, peppers and pink radish plants both grow in a mix of peat moss and man-made asteroid soilthe researchers reported in July journal of planetary science.
Scientists have previously Growing crops in lunar dirt (SN: 5/23/22). But the new study focused on “carbonaceous chondrites that are known to be rich in volatile sources — especially water,” said astroecologist Shirley Fieber-Bayer of the University of North Dakota Grand Forks. These meteorites and their parent asteroids are also rich in nitrogen, potassium and phosphorus — key agricultural nutrients. Shattering these types of asteroids, perhaps as part of space mining efforts, could provide a ready supply of agricultural materials in space.
Fieber-Beyer purchased a material that mimics the composition of space rocks and gave it to her graduate student, Steven Russell. “I said, ‘Okay, plant me some plants.'”
Russell, now an astrobiologist at the University of Wisconsin-Madison, chose a variety of turnips, lettuce and peppers — all grown on the International Space Station. He, Fieber-Beyer and their colleague Kathryn Yurkonis, also from the University of North Dakota, compared how the plants grew in artificial asteroid soil, peat moss and various mixtures of the two.
Peat moss keeps soil loose and improves water retention. In all mixtures with peat moss, plants grow. However, the artificial asteroid soil itself would be compacted and unable to retain water, so plants could not grow.
Next, Fieber-Beyer will attempt to grow hairy vetch seeds in artificial asteroid dirt, allow the plants to rot, and then mix the dead plant matter throughout the soil. This ensures the soil doesn’t compact, she said. Plus, the seeds are much lighter in weight than peat moss, making them easier to carry into space to aid any future farming endeavors.