China’s lunar probe has found traces of water in lunar soil samples, scientists said, as the country steps up its ambitious space program. The Chang’e-5 rover completed its mission in 2020 and returned to Earth with samples of lunar rocks and soil.

Lunar samples “revealed the presence of traces of water,” a group of scientists from Chinese universities wrote in the journal. Natural Astronomy, It was published Monday. NASA’s infrared detector confirmed the presence of water on the moon in 2020, and scientists found traces of it in a recent analysis of samples from the 1960s and 1970s.

But the Chang’e-5 samples were taken from “a much higher latitude,” the Chinese scientists write, providing new clues about how water forms on the lunar surface. The samples suggest that “water molecules may be stored as hydrated salts in the sunlit regions of the moon.”

Chang’e-5 was the world’s first mission to collect samples from the Moon in forty years.

This comes after Chang’e-4’s historic first landing on the far side of the moon in January 2019. Last month, the lunar probe Chang’e-6 completed its mission to collect the first samples from the far side of the moon.

Over the past decade, China has poured huge resources into its space program, making ambitious efforts to catch up with traditional space powers the United States and Russia. It has become the third country to build a space station and send astronauts into orbit. China also plans to send a manned mission to the moon by 2030 and establish a lunar base.