Scientists say Earth's core is changing shape

Dust off your old science textbook from grade school and you'll probably find a familiar illustration of the Earth sliced in half, revealing the planet's layers, from the crust down to the core - perfectly circular concentric rings. But a study published yesterday in the journal Geoscience Nature suggests that the Earth's core may be changing shape. Host Marco Werman speaks with geophysicist Jessica Irving at University of Bristol in the UK, who read the study.