On January 3, 2019, China's Chang'e-4 lander touched down on the far side of the moon and deployed the Yutu rover. In addition to its many instruments, the rover carried an important science experiment known as the Biological Experiment Payload (BEP). Over the next eight days, this payload conducted a vital experiment where it attempted to grow the first plants on the moon. Included in the payload were cotton, potato, arabidopsis, and rape seeds, along with fly eggs, yeast, and 18 ml (0.6 fluid oz) of water, which was kept at a constant atmospheric pressure.