The Chang’e-4 biosphere experiment which produced the sprouting of cotton seeds on the far side of the Moon has ended, according to scientists involved in the pioneering test.
Images released on Tuesday and taken on January 7, show a sprouting of cotton seeds in the lunar canister within a 2.6 kg mini biosphere aboard the Chang’e-4 lander, with the development receiving global coverage. Meanwhile, sprouts in an Earth-based control experiment were shown to be evidently performing much better.
The canister is aboard the Chang’e-4 lander which made its historic landing on the far side of the Moon on January 3, with the experiment initiated hours after landing.
Along with cotton, five other species—seeds of rapeseed, potato and Arabidopsis, fruit fly eggs and yeast—were also aboard, but neither images nor clear reports on these have been released.
It is clear however that all six species involved in the experiment will have become frozen after the onset of lunar nighttime on at the landing site in Von Kármán crater on January 13 as, with no power supply, the temperatures quickly dropped below zero degrees Celsius and could fall as low as -180 degrees C.
Liu Hanlong, head of the experiment at Chongqing University, said at a Chongqing government press conference on Tuesday that the temperature inside the 1-litre-capacity canister had reached -52 degrees Celsius and the experiment had ended.
According to Liu, the experiment did not carry a battery and could not continue environmental control during the lunar nighttime. The lack of battery was possibly due to mass constraints for the mission and the lander’s own power demands.
The experiment, consisting of the canister, the six species, water, soil, air, two small cameras and a heat control system, ran for 212.75 hours.
When lunar daytime begins the temperatures will rise and the organisms will gradually decompose. This will take place in the enclosed canister and will not affect the lunar environment, the China National Space Administration (CNSA) stated.