Iron catastrophe

The iron catastrophe was a crucial event early in the History of Earth with respect to the future of life on our planet. When the mass and temperature of the newly forming planet reached a critical level, the denser iron, held in the outer layers, sank towards the centre of the planet to form the core; this event is a part of planetary differentiation. The gravitational potential energy released by the sinking of the dense NiFe globules increased the temperature of the protoplanet above the melting point resulting in a global silicate magma which accellerated the process. This event occurred at about 500 million years into the formation of the planet. [Charles Frankel, 1996, "Volcanoes of the Solar System," Cambridge University Press, p -7-8, ISBN 0521477700]

This large spinning mass of super-hot metal is responsible for the Magnetosphere, which protects the earth from the most harmful components of Solar Radiation coming from our sun, and allowed life to evolve. The magnetosphere protects both life and our atmosphere to the present day and distinguishes our planet from one of its closest celestial neighbours, Mars, which did not experience its own iron catastrophe.

Another theory suggests Mars did once experience it's own iron catastrophe and was once shielded by a magnetosphere. Mars has simply cooled faster than the earth and has solidified it's spinning iron center into sync with it's continental crust, gradually shutting down its Magnetosphere. Finding signs of liquid water once existing on Mars would suggest that it once had it's own magnetic shield to keep the water in the atmosphere of the planet from being blown into space by solar wind.

References

External links

* [http://rainbow.ldeo.columbia.edu/courses/v1001/first3bill.html Lecture]

ee also

*Rain-out model