. Scientists from Oxford believe that if a Mercury-like Planet had not come into contact with Earth billions of year ago, the magnetic field would not have created allowing too much cosmic radiation to reach the surface, which could have prevented life from developing and prospering. Details of the latest research by the researchers from the University’s Department of Earth Sciences were published in Nature. Professor Bernard Wood and Dr. Anke Wohlers have concluded that a significant impact with Mercury-like planets long ago must have caused Earth’s core heat to rise. Rare-earth metals in the Earth’s core cannot have resulted from meteorite impact. It must have involved a large collision with an enormous Mercury-like planet. Because the Earth’s core heats up, it drives the flow of molten steel in its centre, which then generates the magnetic field, which deflects harmful cosmic radiation from hitting the planet’s surface. According to the authors, it is highly unlikely that life would have existed as it exists today if this radiation hadn’t been diverted. Two rare earth metals, samarium (and neodymium) are found in greater amounts in Earth’s crusts and mantles than in meteorites. These levels of rare earth metals cannot have been caused by meteorite impact. The Earth’s ratio of rare earth metals suggests that something more happened billions of thousands years ago. According to the authors, a Mercury-type planet of high sulphur content crashed into Earth. This would have made it a part of our planet. They wrote that the sulphur would have caused a chemical mutation which eventually resulted in Earth having a balance of samarium, neodymium. The Earth’s magnetic field, which deflects much of the sun’s radiation, would remove the protective ozone layer. Image: unc.edu. There is no life on Earth’s surface, and there are no water or life. But, what’s more, life (including humans!) would not exist without the magnetic field. The heat that drove the geo-dynamo that formed our planet’s magnet field was generated by the collision of an Earth with sulphur. The magnetic field helps to deflect cosmic radiation. It is essential for liquid water to be present on the surface. Without it, life wouldn’t exist. The researchers say that if the current samarium-to-neodymium ratio in our planet’s crust and mantle could not have come merely form meteorite bombardments, it may have been the result of a major collision between Earth and a smaller, Mercury-like, sulphur-rich planet. The Mercury-like planet would have integrated with Earth and produced thorium, uranium, and the heat necessary to fuel the circulation of the molten iron, creating the magnetic field. In an Abstract in the journal, Wood and Wohlers concluded: “We show here that addition of a reduced Mercury-like body (or, alternatively, an enstatite-chondrite-like body) rich in sulfur to the early Earth would generate a superchondritic Sm/Nd in the mantle and an 142Nd/144Nd anomaly of approximately +14 parts per million relative to chondrite. The sulfur-rich core would also partition uranium strong and thorium lightly, providing a significant part of the “missing” heat source for geodynamo. Richard Carlson, of Carnegie Institution for Science, Washington D.C. wrote in an accompanying letter that the computer model developed by scientists appeared to resolve the issue of missing heat source. It raises new questions about how Earth got to where it is today. Dr. Carlson stated that the energy source driving the Earth’s core magnetic field has been an ongoing topic of debate. Wood. Nature. Published 15 April 2015. DOI: 10.1038/nature14350. Richard W. Carlson. Nature. Published 16 April 2015. DOI: 10. 1038/520299a.
Mercury-like planet collided with Earth, then there was Life
