China's lunar rock samples show lava flowed on moon 2B years ago: researchers

China's lunar rock samples – the first moon rocks returned to Earth in more than 40 years – show lava flowed there 2 billion years ago, according to scientists.

"Orbital data indicate that the youngest volcanic units on the moon are basalt lavas in Oceanus Procellarum, a region with high levels of the heat-producing elements potassium, thorium and uranium," the team wrote. 

China's Chang'e 5 lander used a drill to collect samples about 170 kilometers east-northeast of Mons Rümker – a large volcanic complex – and used radioactive dating to determine their age.