The Chang’e 5, an unpiloted spacecraft, travelled to the moon in December 2020. A robotic arm picked up moon rocks, and those rocks have now returned to Earth with the Chinese craft. This means that for the first time in nearly half a century, scientists have new moon rocks to study.
Chang’e-5 samples include volcanic glass beads. Scientists believe these rapidly cooled glass droplets are the ejecta of volcanic vents called “Rima Mairan” and “Rima Sharp.”
In the moon’s low gravity, volcanic ejecta can end up rather far from the vent. The vents named above are located roughly 230 and 160 kilometers southeast and northeast of the Chang’e-5 landing site, respectively. That is: 143 and 99 miles.
Strange New Worlds:
The volcanic beads provide evidence of an ancient, hot moon which still harbored erupting volcanoes. The rocks are also helping calibrate the means that astronomers use to guesstimate the age of lunar features. The current models seem to work well for features more than 3 billion years old, or less than 1 billion years old. But this leaves 2 billion year gap in astronomers’ efforts to recreate the history of the lunar surface. Many of the newly sampled rocks seem to be 2 billion years old, which puts them in the middle of the gap.