Chang'e-4 is due to launch later this year and if all goes to plan, it will be the first lunar probe to touch down on the dark side of the Moon. Perhaps even more excitingly, it will also be the very first attempt to grow flowers on the Moon’s surface.
This is all part of China’s “mini-biosphere project”, led by Chongqing University.
"We want to study the respiration of the seeds and the photosynthesis on the Moon," Liu Hanlong, chief director of the experiment and vice president of Chongqing University, told reporters.
The team hopes the mission will provide useful intel that could one day help us set up a colony on the Moon.
"Our experiment might help accumulate knowledge for building a lunar base and long-term residence on the Moon," Liu added.
In December, potato and Arabidopsis (a member of the mustard family) seeds will be placed in an aluminum alloy tin measuring just 18 centimeters (7 inches) by 16 centimeters (6 inches) before hitching a lift on the lunar lander and rover. The tin will also carry silkworm cocoons, water, air, soil, and electrical equipment to record the experiment.
Once it's reached its destination, a tube inside the tin will divert natural light from the surface of the Moon and onto the seedlings, triggering photosynthesis. The plants will emit oxygen, feeding the silkworms who in turn exhale carbon dioxide and leave waste, feeding the plants.
"Why potato and Arabidopsis? Because the growth period of Arabidopsis is short and convenient to observe. And potato could become a major source of food for future space travelers," said Liu. (Though sweet potatoes may make better alternatives.)
The whole experiment will be captured on film and transmitted back to Earth where us Earthlings can watch it on a live stream.
While the team faces many challenges, sunlight isn't one of them. The "dark" side of the Moon was so named because it is not visible to us from Earth but it’s actually a bit of a misnomer. It receives just as much sunlight as the visible side. More problematic is the Moon's gravity, which is just 16 percent of what we experience on our blue planet.
Another major challenge is the climate, particularly the extreme temperatures, which could be a death trap to plants used to a more balmy Earth. On the Moon, temperatures can climb to more than 100°C (212°F) and plummet below -100°C (-148°F), so the team will be controlling the mini biosphere to keep temperatures between 1 and 30°C (34 and 86°F).
Technically, astronauts have grown plants in space before – on the International Space Station and in China's Tiangong-2 space lab – but this will be the first time plants are cultivated on the Moon's surface.
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