The moon may have received a volcanic facelift, making it more than 100 million years older than rocks collected from its surface might suggest, a new study finds.
There are a number of reasons to suspect the moon is older. For instance, there are rare lunar zircon minerals that suggest the moon was born about 4.5 billion years ago. In addition, many scientists who have created simulations of planetary formation suggest that a collision huge enough to create the moon was unlikely to happen a quarter-billion years after the origin of the solar system. Although giant cosmic impacts were common in the solar system's earliest days, the orbital dynamics models suggest that most of the massive rocks behind such titanic clashes were swept up into larger bodies by about 4.4 billion years ago.
