Slashdot Mirror
Scientists Calculate the Moon To Be 4.51 Billion Years Old (go.com)
Scientists used rocks and soil collected by the Apollo 14 moonwalkers in 1971 to calculate the age of the moon. It turns out that it is much older than scientists suspected, coming in at 4.51 billion years old. ABC News reports: A research team reported Wednesday that the moon formed within 60 million years of the birth of the solar system. Previous estimates ranged within 100 million years, all the way out to 200 million years after the solar system's creation, not quite 4.6 billion years ago. The scientists conducted uranium-lead dating on fragments of the mineral zircon extracted from Apollo 14 lunar samples. The pieces of zircon were minuscule -- no bigger than a grain of sand. The moon was created from debris knocked off from Earth, which itself is thought to be roughly 4.54 billion years old. Some of the eight zircon samples were used in a previous study, also conducted at UCLA, that utilized more limited techniques. Melanie Barboni, lead author of the study from the University of California, Los Angeles, said she is studying more zircons from Apollo 14 samples, but doesn't expect it to change her estimate of 4.51 billion years for the moon's age, possibly 4.52 billion years at the most. The study was published today in the journal Science.
this is all a guess, they actually have no idea.
This also puts the age of both the earth and the moon at "when the first rocks formed", not "when the celestial body formed" which imho is when a significant amount of space debris, possibly molten, clumps together to form something resembling a planet. There's probably no way to really figure that one out.
As the moon is supposedly formed from material from the earth, it could be argued to be the same age (it being from the same clump of material, plus some of the asteroid that caused the split - which in turn may have contained material that solidified much earlier, of course).
In that line of thought, how can we be sure that these moon rocks and earth's oldest rocks are really formed on these bodies and are not fragments of much older objects that were caught in the respective gravity fields?
...I learned from watching "Creature From the Black Lagoon." That movie has surprisingly accurate science for a Universal monster flick. Double-checking fossil age estimates against the surrounding rock. Whoa, I didn't catch that when I was eight! The leading-man "good guy" scientist is searching for additional information about the transition from water-breathers to air-breathers in the evolutionary record for tidbits that could prove useful in adapting the human body for deep-space exploration.