This is pure science geek type stuff but it seems that our estimations of how old the Moon is might be off by a tad.
Scientists at Lawrence Livermore National Labratory have been examining the rocks collected by the Apollo 16 astronauts and they think that the Moon could be 60 million years younger than previously thought.
Lars Borg from Livermore says that its new age would put it closer to the 4.4 billion year of age of some of the oldest known minerals on our Earth, which are thought to be zircons at Jack Hills in Western Australia. So the assumption now is that the oldest crusts on both the Earth and the Moon were formed around the same time.
The prevailing hypothesis for the moon’s origin, the giant impact theory, involves a collision between the early proto-Earth and another proto-planet called Theia, which was about the size of Mars. Melted ejecta and debris from this impact was thrown into space, eventually coalescing over millions of years to form the moon.
As the moon cooled, this magma solidified into different mineral components with lunar crustal rocks called ferroan anorthosites (FAN) being the oldest. But scientists have had difficulty dating FAN samples.
Borg and colleagues used new refining techniques to analyze isotopes of lead and neodymium in their 1.88 gram sample of FAN from the lunar rock collection at NASA’s Johnson Space Center. Their figure of 4.36 billion years pinpoints the time at which the sample crystallized. This figure is 200 million years after formation of the solar system and significantly later than assumed by most lunar formation models.
“It’s the first time a single sample of FAN yielded consistent ages from multiple isotope dating techniques,” Borg said. “Previous attempts to date these rocks have relied on just one isotopic clock which can be contaminated putting the age in error. So we started with the idea that we would get multiple age samples so we could have confidence it reflected the crystallization age of the sample.”
Guess that means the Moon will have to go back to being carded the next time it heads to the bar.