Potassium-40 heats up Earth’s core (May 7)
http://physicsweb.org/article/news/7/5/4
Radioactive potassium could be a significant source of heat in the Earth's core. V Rama Murthy from the University of Minnesota and colleagues have shown that potassium-40 can exist in the core of the Earth and provide heat via its radioactive decay. The result could have important implications for theories of thermal evolution of planetary cores and the origin of geomagnetic fields (V Rama Murthy et al. 2003 Nature 423 163).
-----------------------------