Introduction: How to Simulate Growing a Rocket Salad on Mars
If you've been following along with what's happening in space exploration, then you may have heard that various space companies are planning manned missions to Mars between 2025 and 2035. As part of this planning process, scientists are experimenting with how humans will survive on the red planet. They must contend with a lack of oxygen, freezing temperatures, radiation, just to name a few, significant challenges for survival.
After watching the movie, Mars, with Matt Damon, I became interested in how one might grow food on a planet with soil full of lead, cadmium and arsenic and very very salty water (saltier than our oceans here on Earth).
Mojave Martian Simulant (MMS)* can be found naturally as whole rocks in a volcanic formation near the town of Boron, California, in the western Mojave desert. The iron-rich basalt closely resembles the type of soil found on Mars (minus the heavy metals toxic to humans). This desert rock was used by NASA and JPL scientists to simulate the surface of Mars for testing the Mars Phoenix landing and now it's also used by scientists to simulate growing plants on Mars. Scientists have also used rock found in Hawaii as a simulant soil.
One of the plants that scientists have been growing is called "Rocket" or Arugula, a leafy green vegetable. I couldn't think of a more aptly named plant for testing out growing plants that may one day be grown on a distant planet.
Although this is a simple project, it spurs further inquiry into how humans will survive on Mars, because let's face it, kids today may end up there.
I hope that you enjoy this project and try out different types of plants to grow in the Mars simulant soil!
* Martian regolith simulant (or Martian soil simulant) is a terrestrial material that is used to simulate the chemical and mechanical properties of Martian regolith for research, experiments and prototype testing of activities related to Martian regolith such as dust mitigation of transportation equipment, advanced life support systems, and in-situ resource utilization.
Step 1: Materials and Tools
Gather the following materials:
- Small pot that will hold 3 ounces of soil
- 3 ounces Mojave Mars Simulant soil. Three options:
- Purchase for $0.99 from The Martian Garden
- Dig soil up in Boron, California
- Make it yourself based on these instructions
- Arugula is a cool-season annual, meaning that it is best to plant in spring or fall. Plant in full sun and fertile, well-drained soil. Water when the soil gets dry.
- We used a growing container called Click & Grow that has an attached light so that we could ensure a consistent amount of light each day. It also waters automatically because I am very forgetful about watering. It's not necessary if you have adequate light and remember to keep the soil moist and well drained.
Step 2: Fill Pot With Mars Simulant Soil
The Mars simulant soil is like no soil you've ever worked with, however, there is no need to treat it special or to be nervous.
- Pour the soil into the pot
- Use your finger to level the soil
Step 3: Moisten the Soil
Before you plant the seeds, sprinkle water into the soil. 3 ounces of soil isn't a lot, so you don't need a lot of water. We're not making a mud bath!
Step 4: Sow Your Seeds
Sowing the seeds is straightforward; we didn't do anything special.
- Make a little indent with your finger
- Deposit 5 seeds into the hole with a small space between each
- Cover the hole with a bit of soil
- Give it a gentle pat
Step 5: Label Your Pot
Write the following on your label:
- Name of the plant (Arugula or Rocket if you're feeling spacey)
- Type of soil (MMS: coarse or MMS: fine)
Step 6: Pot Placement
Arugula doesn't do well in really hot weather (the leaves become very bitter) hence the recommendation to plant it in spring or fall.
Your arugula needs full sun or to lengthen the season, give it midday shade.
Don't forget to keep the soil moist!
Step 7: Chillax
Now's a great time to take a nap, visit your local space agency, learn more about terraforming on Mars or to watch the Mars movie.
Step 8: Harvest
Arugula grows very fast. We sowed our seeds on June 4th and they started germinating on June 6th. All told it will take about 3-4 weeks before your Rocket plant is full grown and ready to harvest.
The plant will grow 6 - 12 inches tall and in the shape of a rosette.
Depending on the size of your pot, you may decide to transfer your plant to a bigger pot or garden.
You can pull it up when the plant starts to send up a bloom stalk from the center, or you can continue harvesting the leaves until they taste too strong.
Pick only the outer leaves, so the plant remains intact and usable for weeks to come. Harvest often to encourage new growth.
Note: Arugula flowers are really pretty and a great tasting edible flower.
Photo by Juandoso