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!!

Mercury

• The out-liner of the inner planets

• Has a high density, molten core, magnetic field, and a big core

Thoughts on the mysteries

• 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

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