The magnetic microstructure of the nickel-iron alloy leads to a compression of the field lines in the centre. (Image: A. Palau/ICMAB) Dr Anna Palau from the Institut de Ciencia de Materials de ...

THE effect known as the Widmanstatten structure is shown most clearly in those meteoric nickel-iron alloys in which the percentage of nickel lies between certain limits, roughly, from 7 to 14.

Earth’s diameter is about 7,900 miles (12,750 km). The planet’s internal structure comprises four layers: a rocky crust on the outside, then a rocky mantle, an outer core made of magma and a ...