The rock samples brought back from the Moon in December by China's Chang'e-5 mission were really young.
It's all relative, of course, but the analysis shows the basalt material - the solidified remnants of a lava flow - to be just two billion years old.
Compare this with the samples returned by the Apollo astronaut missions. They were all over three billion years of age.
The findings are reported in the journal Science.
China's robotic Chang'e-5 mission was sent to a site on the lunar nearside called Oceanus Procellarum.
It was carefully chosen to add to the sum of knowledge gained from previous sample returns - the last of which was conducted by a Soviet probe in 1976.
