After almost being declared dead, China's Jade Rabbit lunar rover has uncovered something astronauts and earlier rovers missed: a new type of moon rock. While exploring an impact crater in the Mare Imbrium—what Motherboard calls the "right eye" of the "Man in the Moon"—the rover discovered basalt with "unique compositional characteristics," researchers write in a study published in Nature on Dec. 22. Earlier moon rock samples were either high or low in titanium, but the new sample's titanium levels fall somewhere in between, reports Quartz. "The diversity tells us that the moon's upper mantle is much less uniform in composition than Earth's," a researcher tells the Guardian. "And correlating chemistry with age, we can see how the moon's volcanism changed over time."
Motherboard explains that something sets this Mare Imbrium "excursion" apart from previous ones. "The rover's mothership, the Chang'e 3 lander, happened to land in a small crater called Zi Wei. ... This collision kicked up a lot of ejecta and material from several periods in the Moon's history, so [the Jade Rabbit] has a wide range of sample ages to study." Which is doubly lucky, as malfunctions the Jade Rabbit experienced prevent it from moving. Chang'e 5, set to land on the moon in 2017, will eventually return with lunar samples, reports the New York Times. (A new definition could make the moon a planet.)