A biology experiment on board China’s recent Moon lander has sprouted tiny cotton plants, marking the first time that humans have grown plants on the lunar surface, Xinhua reports. Though people have grown flowers and other plants in Earth orbit before, such experiments had never been attempted on other planetary bodies besides Earth.

The news comes nearly two weeks after China’s Chang’e-4 mission became the first human-made vehicle to land softly on the far side of the Moon. Chang’e-4, which consists of a lunar lander and rover, is carrying multiple experiments and technologies to study the Moon’s terrain. The lander also has a 6.6-pound (3-kilogram) canister that contains six different biological species that are intended to germinate and grow. Those include seeds for cotton, rapeseed, potato, and Arabidopsis. Fruit fly eggs and yeast are also in the canister, forming a tiny ecosystem, according to Weibo.

First in human history: A cotton seed brought to the moon by China's Chang'e 4 probe has sprouted, the latest test photo has shown, marking the completion of humankind's first biological experiment on the moon pic.twitter.com/CSSbgEoZmC — People's Daily, China (@PDChina) January 15, 2019

Soon after Chang’e-4’s landing, the biology experiment was turned on and given water. Now, China has released pictures of the payload taken on January 7th, which show sprouting cotton plants. The country has also shown pictures of a control version of the experiment located on Earth, which shows much more substantial growth. It seems that none of the other species in the canister on the Moon are growing, according to Xinhua. “This is limited in what it’s doing, but also unique from analog experiments on the Earth,” Andrew Jones, a freelance reporter who is following China’s space program, tells The Verge.

The experiment, developed by researchers and students at Chongqing University, is not the first time plants have been grown in a space environment. Astronauts have already grown multiple species of plants on board the International Space Station, including zinnia flowers, lettuce, and sunflowers. However, this is the first time that plants have been grown in the unique lunar environment. Compared to our planet, the Moon has one-sixth of the gravity, extreme temperature variations, and much higher levels of radiation.