12 September, 2010

APOD: It's Nuclear!

My dear, my cherished, my beloved Suzanne sent me this link tonight under the heading "Geology for you."  And what did I find but an Astronomy Picture of the Day that's totally nuclear geology:

Oklo: Ancient African Nuclear Reactors
Credit & Copyright: Robert D. Loss (Curtin U.)
Oh, yes, my darlings, that's right - ancient fission reactors in ancient uranium deposits in equatorial Africa.  Two billion years ago, groundwater mixed with uranium ore, and we had fission!  Natural freakin' fission.  How awesome is that?  Back in those days, the uranium hadn't decayed to the point where you needed humans to turn it into fissile material.  Just add water, and you had yourself a nuclear chain reaction.

We have learned a valuable lesson here today: be careful where you pee in the wilds on a young planet.

Suzanne's provided us with more than one lovely picture today.  Go check out her "After Sunset."  No matter whether you're having a good day or bad, it's exactly what you need.


Suzanne said...

*blushing* thought you would like it hon -- make me do a geo geek squee when i saw it

Lyle said...

Given that this is caused by the differential rates of decay of U-235 and U-238 730 million years versus 4.5 billion, it is likely that a lot of this sort of thing went on in the Archean. (Pre 2.5 billion years). However given that preservation of rocks that old is somewhat spotty, its likely that the evidence is now eroded away or the like.