Yeah, but imagine how he felt the day after.
“What did you do yesterday?”
“I found the oldest rock on Earth!”
“Nice! What’re you going to do today?”
“Um… “

Count the years. It’s been awhile.

One of the minerals brought back is now called “armalcolite”, named for Armstrong-Aldrin-Collins, who brought it back. It doesn’t occur on Earth.

Those of you with dating problems – sorry, not that kind – can actually get the info from a practicing Christian who knows when to read his instruments. See “Radiometric Dating – a Christian View”. It’s remarkably free of dogma.

You can also go find a copy of Nuclides and Isotopes, by GE Nuclear Energy. Your library might have one.

This stuff is studied so intently I don’t have the words to explain it.

Moon rocks have certain characteristics which make them noticeably different from Earth rocks, at least for geologists. For examples: they lack water (all Earth rocks, even those spat from volcanoes, contain water bound into their chemical structure); they’ve been subject to no weathering by air or water; and their exposed surfaces show “zap pits” – tiny craters caused by the impact of dust particles at several kilometres per second.

But… If some cataclysmic collision created the moon from the collision of Earth and another planet, wouldn’t all the date markers be reset?

Even if this were true (and as Torbjörn says, it isn’t), we have other lines of evidence for the age of the solar system as a whole, which constrain the age of the earth under any reasonable assumptions. We have estimates for the age of the sun which depend on quite different reasoning, but agree very well with the planets forming shortly after the sun. Furthermore, we can see solar systems in various stages of formation, so we know are ideas aren’t completely out of whack (although there are plenty of puzzles and surprises!)

Of course, when creationists see the E word in “stellar evolution” they reject the whole field. Did you ever see a star turn into a cat ? I DON’T THINK SO!

I can imagine how much mileage Apollo moon hoax believers will get from this, since a distinction between Earth rocks and moon rocks is that rocks from the moon show a greater age than rocks on Earth.

By the way, is there a theoretical basis on the fact that the radioactive dating is reliable other than the consistent results the rocks give when one dates it?

AFAIU one can use self-calibrating isochron dating.

@ Kevin, Ray, Tony, Lee:

Don’t forget isotope balances.

Can you really say the earth was formed before the impact that created the moon? Surely without that impact, the composition of this planet would be different. I’d think that impact was a key event in the formation of this planet.

In the same way we can get an idea of the age of the Earth by the building scraps – meteorites. These left-overs from the time the planets condensed out of the accretion disk can give us an idea of just when all this happened. So meteorites were used to determine the age of the earth through radiometric dating.

Radiometric dating of moon rocks agrees with the estimate from meteorites. It’s a little younger than the meteorites, but not terribly so. Then there’s the microscopic remnants found in Australia, if I recall correctly – and this newly dated slab of rock in Quebec.

I’ve also touched the “moon rock” at the Smithsonian. Exactly how we do know its really a moon rock? Could be any old piece of granite/basalt/whatever with a nice plague for all we know.

I guess it’s just a matter of faith.

OK, I’ve always wondered this, so I have to ask. How do we know how old the Earth is? My understanding was that it’s from rock finds like this, and dating the moon rocks which give the same answer. But… If some cataclysmic collision created the moon from the collision of Earth and another planet, wouldn’t all the date markers be reset? Like the carbon ratios are continuiously reset in living creatures until they die? And obviously the Moon would be the same age, then, right? So the Earth could be much older, and just got a face lift of sorts by the moon collision. What’s wrong with that logic?

I smell a quote mine!