Mercury And Theia

There is a saying about "putting two and two together". Why don't we see if we can apply it today?

It is widely believed that a planetary object once collided with earth. The fragments of this object collected together by gravity to form the moon. The object has been named "Theia". There is also believed to be parts of Theia embedded in earth's mantle.

There is reason to believe that the moon formed from such a collision. First, the moon lacks a large iron core like the planets have. Iron is as far as the ordinary fusion process goes, in the star that preceded the sun that exploded in a supernova. This is why iron is so abundant in the inner Solar System. It is the most abundant element on earth by mass. We know that the moon is made of rock, lacking a large iron core, because it is 1/64 the volume of the earth but only 1/81 the mass of the earth. The moon also has practically no magnetic field, which is created by an iron core.

Another reason for believing that the moon formed from fragments is how it's surface gravity varies from place to place. This actually caused the first astronauts that landed on the moon to miss their intended landing site by several km.

My geology theory expands on this concept of Theia to explain the continents as part of the planetary object that remained on earth, instead of being hurtled back into space to form the moon. 

An abbreviated version of the geology theory, on this blog "Geology Theory With Satellite Imagery And Maps", March 2024.

But how could such a mass of rock like Theia have formed in the Solar System without an iron core? This would be completely unlike the rest of the inner Solar System. Or is what remains of Theia, including an iron core, still out there somewhere?

Now let's go to another mystery in the Solar System, that of the planet Mercury. The smallest and closest planet to the sun has the opposite mystery to the missing iron core of the moon. The iron core of Mercury occupies a much higher proportion of the planet's cross section than that of earth. Mercury's rocky mantle and crust takes up a much lower proportion of it's cross section than that of earth.

The following diagram represents the cross section of the earth. The inner red circle is the iron core and the outer blue circle is the rocky mantle and crust.

In the following diagram the double circle at left represents the cross section of Mercury. The inner red circle is the core and the outer blue circle represents the rocky mantle and crust. The circle at right represents the moon, made of rock but without a significant iron core.

There is speculation that Mercury must have underwent some type of collision to have lost much of it's former rocky mantle. I can't see that anyone has "put two and two together". What if Mercury, which is the smallest planet, is the remainder of Theia, which collided with the earth to result in the formation of the moon? The collision caused it to lose orbital energy so that it fell into a lower orbit closer to the sun, where we see it today as Mercury.

Something else that is interesting is that Mercury has undergone a tremendous impact in it's past. There is an impact crater, known as Caloris, that is one-third of the diameter of the planet. The impact was so great that it distorted the terrain on the diametrically opposite side of the planet. The crater is said to be from relatively recently in the planet's history, because it doesn't contain as many craters as the terrain outside the crater, but this could be due to a factor like lava emerging from the crater and possibly the crater is from the impact with earth.

I think this deserves some consideration because it is just "putting two and two together".