Editing Planetary core (section)

====Mars====
Mars possibly hosted a core-generated magnetic field in the past.<ref name="Hauck and Van Orman 2011"/> The dynamo ceased within 0.5 billion years of the planet's formation.<ref name="Williams and Nimmo 2004"/> Hf/W isotopes derived from the martian meteorite [[Zagami]], indicate rapid accretion and core differentiation of Mars; i.e. under 10 million years.<ref name="Halliday and N. 2000"/> Potassium-40 could have been a major source of heat powering the early Martian dynamo.<ref name="Murthy, van Westrenen and Fei 2003" />
  
Core merging between proto-Mars and another differentiated planetoid could have been as fast as 1000 years or as slow as 300,000 years (depending on the viscosity of both cores and mantles).<ref name="Monteaux and Arkani-Hamed 2013" /> Impact-heating of the Martian core would have resulted in stratification of the core and kill the Martian dynamo for a duration between 150 and 200 million years.<ref name="Monteaux and Arkani-Hamed 2013" /> Modelling done by Williams, et al. 2004 suggests that in order for [[Mars]] to have had a functional dynamo, the Martian core was initially hotter by 150&nbsp;[[Kelvin|K]] than the mantle (agreeing with the differentiation history of the planet, as well as the impact hypothesis), and with a liquid core potassium-40 would have had opportunity to partition into the core providing an additional source of heat. The model further concludes that the core of mars is entirely liquid, as the latent heat of crystallization would have driven a longer-lasting (greater than one billion years) dynamo.<ref name="Williams and Nimmo 2004"/> If the core of Mars is liquid, the lower bound for sulfur would be five weight&nbsp;%.<ref name="Williams and Nimmo 2004" />