RIP lunar cotton sapling: First plant on moon dies

Barely after it had sprouted a leaf, the cotton plant onboard the Chinese lunar lander Chang’e-4 has died due to temperatures as low as 170ºC. A cotton seed had germinated on the craft after it had touched down on the perpetually dark half of the moon, Chinese media reported on Tuesday.

The historic feat was billed as a “giant leaf for mankind” as China’s state-run media reported that a small green shoot was observed growing aboard the lander. The sprout was growing inside a canister, scientists at the Advanced Technology Research Institute at Chongqing University informed, based on photographs released by ARTI.

However, Professor Xie Gengxin of Chongqing University, who led the design of the experiment, said its short lifespan had been anticipated. “Life in the canister would not survive the lunar night,” Xie said.

What bloomed

Before China finished packing up its Chang’e 4 lunar lander for a never-before-accomplished journey to the far side of the moon, scientists slipped in a small tank holding plant seeds.  The cargo included an airtight container that carried bioscience test loads, including one called a “moon surface micro-ecological circle”.

The team from Chongqing University designed a “mini lunar biosphere” with rapeseed, rock cress and potato seeds, yeast and fruit fly eggs besides cotton, to lay the foundation for human settlement.

The yeast, acting as a decomposition agent, processed waste from the flies and the dead plants to create an additional food source for the insects.

The test load was put inside an 18 cm-long cannister with lattice, containing optimal quantities of air, water, and soil. It was sealed from the extremes of temperature and strong radiation on the moon, and equipped with specially designed tubes carrying natural Earthlight for photosynthesis. The airtight container was designed to maintain a temperature of 25°C.

Images initially sent back by the probe showed a cotton plant exhibiting healthy growth although none of the other plants had sprouted, the university said.

“This is the first time humans have done biological growth experiments on the lunar surface,” Xie had told the media on Tuesday. He said that the six spieces that were chosen were small and could grow in a confined environment. They were also hardy enough to withstand some of the extreme conditions on the lunar surface.

Why it matters

“We have given consideration to future survival in space. Learning about these plants’ growth in a low-gravity environment would allow us to lay the foundation for our future establishment of space base,” Liu Hanlong, head of the experiment, told Chinese media on Tuesday. He said potatoes could be a main source food for space explorers, cotton could be used for clothing, and rapeseed could be a source of oil.

This discovery records stupendous progress in the study of the possibility of life elsewhere in space, and has huge ramifications while planning long-term space missions in future.

Although plants have previously been grown in the International Space Station, this is the first time one grew on the moon. At the ISS, scientists regularly tend plants to study human growth-related changes in microgravity (to diversify astronaut diets in space). Plants and seeds have orbited Earth on and off throughout spaceflight history with the closest instance of vegetation on the moon occurring in 1971, when Apollo 14 carried hundreds of tree seeds to orbit the moon with him. Many of these seeds were later planted back on Earth, becoming “Moon Trees.”

Chang’e-4’s accomplishment, however, stands to open new doors for harvesting food in space using locally extracted water, thus allowing astronauts to sustain longer in space instead of returning to earth to replenish supplies. It may also help in framing the blueprint for growing resources during a future moon colony established by humans.

“We have given consideration to future survival in space. Learning about these plants’ growth in a low-gravity environment would allow us to lay the foundation for our future establishment of space base,” Liu said.

About the Chang’e-4 mission

China became the first country to land a probe on the far side of the moon on January 3 when a rover named Yutu 2 touched down in the South Pole-Aitken Basin, to perform experiments in the moon’s largest and oldest impact crater, Von Kármán. It is believed to be a major step in China’s ambitions to become a space superpower.

One of the purposes of the mission was to test whether plants could grow in a low-gravity and strong radiation environments, a test which appears to have already yielded results. Other tasks of the Chang’e-4 mission include conducting the first lunar low-frequency radio astronomy experiment and exploring whether there is water at the moon’s poles.

What’s next

China’s ambitions for space and lunar exploration aren’t limited to the current mission. Planning a Mars mission around 2020, China’s space agency on Monday announced four more lunar missions including Chang’e-5 which will be launched by the end of the year with a goal to bring moon samples back to Earth, for the first time since the 1970’s.

According to Wu Yanhua, deputy head of the China National Space Administration (CNSA), the Chang’e-6 mission will be designed to bring samples back from the lunar south pole of the moon, followed by probes that will conduct comprehensive surveys of the area. All these missions will also lay the groundwork for the construction of a lunar research base, possibly using 3D printing technology to build facilities, Wu said at a press conference this week.

With the world’s first truly otherworldly plant, despite its premature but anticipated death, China has already made a visible mark on space, in the event of lunar colonisation. The Chang’e missions have already solicited strong disapproval and caution from rival countries including the US, which is currently fundraising to build a Space Force.

The article was updated on January 17, 2019, at 10 am to include the cotton plant’s death.

Prarthana Mitra is a staff writer at Qrius

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