What Happens When Moss Grows in Space

Volker - NASA has a number of new missions, including going back to the moon and maybe even Mars. If astronauts are sent out for long periods of time, they need something to feed themselves. Therefore, we have done a number of plant experiments on space flights to see how the plants respond to zero gravity. We decided to use roof moss because you can pinpoint individual cells and work out the growth mechanism. This is not possible in higher plants as they have millions of cells to look at.

Chris - What are the results so far?

Volker - After growing the moss in space for 14 days, we opened up the containers and found the moss growing in spirals. This is something we hadn't predicted. Originally we thought that it would grow randomly, just like other plants that have been taken into space. On earth, plants are guided by the force of gravity, which ensures they grow in the right direction. Taking gravity away means that they don't know which way to go. The experiments also show that light is not the most important aspect of making sure plants grow upwards. For example, when seeds send up their first shoots they are in the dark, so they only have gravity to guide them.

Chris - How does moss's spiral growth help you understand how plants grow when gravity is present?

Volker - We think the organelles settle in the cell, allowing the cell to know which way is down. I suppose it's quite like a spirit level. These experiments will also help with us to grow other plants in the future. We started with simple moss and can now do similar experiments with more complicated plants. Eventually, we hope to be able to grow lots of plants in space for hungry astronauts !