The possibility of keeping humans alive on Mars has taken a step closer as two young worms are the first offspring in a Martian soil experiment.
A Mars soil simulation has begun by agricultural college Wageningen University & Research. The experiments are seen as crucial in the study that aims to determine whether people can keep themselves alive on the red planet by growing their own crops on alien soil.
To feed future humans on Mars, a sustainable closed agricultural ecosystem is a necessity, the Dutch university states.
Worms will play a crucial role in this system as they break down and recycle dead organic matter. The faeces and urine of the human Martian will also have to be used to fertilise the soil, but for practical and safety reasons researchers are presently using pig slurry.
They have since been observing the growth of the salad leaf rucola, or rocket, in the Mars soil simulation, provided by NASA, to which worms and slurry have been added.
'Stimulated growth'
"The manure stimulated growth, especially in the Mars soil simulation, and we saw that the worms were active. However, the best surprise came at the end of the experiment when we found two young worms in the Martian soil", said Wieger Wamelink of Wageningen University.
"The positive effect of adding manure was not unexpected’, added Mr Wamelink, "but we were surprised that it makes Mars soil simulant outperform Earth silver sand."
Worms are important for healthy soil, not only on Earth but also in future indoor gardens on Mars or the moon.
They thrive on dead organic matter such as old plant remains, which they eat, chew and mix with soil before they excrete it. This waste still contains organic matter that is broken down further by bacteria, thus releasing nutrients such as nitrogen, phosphorous and potassium for use by the plants.
By digging burrows, the worms also aerate and improve the structure of the soil, making watering the plants more effective.
The latter proved to be very important in earlier experiments where water would not easily penetrate the soil. Mr Wamelink confirmed that: "The application of worms will solve this problem".
Feeding humans
To feed the future humans living on Mars or the moon, the project 'Food for Mars and Moon' aims to set up a sustainable agricultural system.
It is based on the presence of soils and water, in the form of ice, on both Mars and the moon.
For the Earth-based research, Wageningen University are using soil simulants delivered by NASA. The simulants originate from a volcano in Hawaii, which represents Mars and a desert in Arizona, which represents the moon.
The experiments started in 2013. The scientists are currently able to grow over a dozen crops, the only crop that has resisted efforts is spinach.
However, crops such as green beans, peas, radish, tomato, potato, rucola, carrot and garden cress all seem possible.
