Formation of Mercury By Triana Henz
In the beginning… • There was a giant cloud of particles within the Milky Way • Particles start to rotate • The cloud starts to collapse on itself • A star is born at the center!!
What takes place in a few Myr? • Accretion Theory takes place • Heavy elements make their way closer to the sun • A temperature difference takes place at about 4 AU, allowing the inner gas to be hotter
Planets • Particles gather to form cosmic dust • Cosmic dust stick together to grow into small planet like objects • The small planet like objects collide with each other • As the dust clears, we have proto-planets!!
The out-liner of the inner planets Has a high density, molten core, magnetic field, and a big core Mercury
Theories have to account mostly for the high density that is observed Most theories take place during the early stages of the solar system Three leading theories: Selective Accretion Post-accretional vaporization Giant impact Stripping Thoughts on the mysteries
Selective Accretion • Enrichment of iron that leads to the high density • Principles: • Needs mechanical and aerodynamic accretion processes • A low chemical equilibrium condensation temperature
Why was iron so rich? • The solar nebula in the feeding zone was naturally rich with iron • Particles were so close to the Sun that it was reducing the other elements to a metallic form that had a high melting point to solidify • This process could explain why Mercury is highly density
Post-accretional Vaporization • After Mercury was formed, the solar winds were strong enough to blow away the original surface • The solar winds would’ve contained intense solar electromagnetic and particle radiation
Giant Impact Stripping • Object crashed into Mercury • Object needs to be about Mars size • The impact had blown away the upper layers of proto-Mercury
Correct Theory? • Depending on when Mercury was impacted, the material ejected would need to go somewhere • Candidates for where the material ended up are the Sun, Venus, and Earth • The Solar Winds would most likely leave a few traces of the proto layers since the Solar Winds wouldn’t be able to make a near spherical object • Chemical equilibrium condensation models for the solar nebula can’t account for a molten core at Mercury’s present orbit or density if formed between .4-1.4 AU • The condensation models also need to take into account why Mercury is the only one that is affected by the lower temperature • To know which of the theories is correct, chemical composition needs to be known of the surface • Each would leave trace evidence of their existence since each has their own unique signature of oxides and iron oxides
One More Thing… • There is no doubt that the position of Mercury gives itself to an unique formation • It has us believing that we’ll know our solar system and all planet formation if we study it closely • And now we look