There are questions about why the Earth behaves in a certain manner. For instance, it’s rather strange that our planet’s magnetic field has lasted for billions of years, why? Could it be that the same materials contained in the planet Mercury, also lie within the Earth’s core? Maybe in the early years of the Earth’s creation, the planet ‘swallowed’ “Mercury-like” materials. Is this possible?
Scientists believe that the Earth formed around the same time as the sun, along with other planets in our solar system. Each heavenly body was formed from gases and dust, birthed with an influx of asteroid material. The whole idea revolved around chunks of rock pulled together to form the hard body and face of each planet.
Although these ideas are popular, there is something that doesn’t fit in. The mantle and crust of the Earth have more samarium than neodymium, the opposite of what most planets contain. Scientists propose that the Earth absorbed a Mercury-like piece of rock, representing its core. This would explain why the Earth’s magnetic field has lasted so long.
Bernard Wood, geochemist of the University of Oxford in England, states:
“A Mercury-like substance added to the Earth at accretion would prove two important points, one pertaining to the magnetic field.”
Studies and Tests
By taking materials and using conditions similar to what occurred during the early years of the Earth’s formation, scientists were able to gauge certain traces of substances. Temperatures were brought to between 2,500 and 3,000 Fahrenheit, and pressures of about 1.5 gigapascals (10 times greater than the lowest point in the ocean).
The substances tested were samarium, neodymium and uranium. These materials are attracted to silicate rock which makes up most of the Earth’s outer core. If the Earth absorbed a Mercury-like body, high in sulfur, it would cause samarium and neodymium to dissolve in iron sulfide and sink down into the Earth’s core. Since samarium is more attracted to silicate rock, which makes up most of the Earth’s mantle and crust, it is less likely to sink to the core. This would explain why there is more samarium than neodymium in the Earth’s substance.
The Earth’s Magnetic Field
The Earth has possessed a magnetic field for over 3 billion years. This magnetic field is the result of the churning metal, in the Earth’s outer core. It’s strange how the core remained molten for so long. If the Earth ‘swallowed’ a Mercury-like rock, rich in sulfur, the uranium in the Earth would have dissolved easier. If this happened, the uranium would sink back to the core and generate heat, keeping the outer core molten – there you have it!
Bernard Wood and Anke Wohlers, both from the University of Oxford, continue their studies to delve deeper into the topic. Stay tuned to learn more about our mysterious planet.