Friday, March 04, 2011

Too much argon 40 on the moon

The decay of radioactive isotope potassium 40 to argon 40 is one of the main ways of finding the age of rocks: see Potassium-argon dating at Wikipedia.
But on the moon, the Apollo missions found much more argon 40 than could be explained by potassium decay. Other explanations don't look so great either, see: On the question of the 40Ar excess in lunar soils.

No comments: