Our moon was formed about 4.5 billion years before. The idea of the astronomers is a protoplanets about the size of Mars (called Theia by astronomers), collided with earth and as a result of that collision our moon was formed. Now where did the remains of Theia go? But it seems now we have got the answer to it.
What is inside our earth?
If we start digging here we won’t be able to go far. Inspite of that we know the structure of our earth to a large extent. We know there is a thin outer crust of our earth. After that a mantle then a liquid outer core and in the center a solid core is present.
How did we find this out?: Its connection is with Seismic waves are created by earthquakes. When there is an earthquake, the movement the speed of these waves depend on what type of material it is passing through. And through that, scientists found out what type of layers are present in our earth.
Solid Inner Core: In-fact the solid, inner core was a surprising discovery. This was discovered by a Danish scientist Inge Lehmaan in 1936, when she saw some seismic waves, ripples of earthquakes, were being reflected.
Magnetic Field: The discovery of solid core was very significant, because of that we came to know why is the earth’s magnetic field present.
There was one another mystery that how did our moon form. As I mentioned we know that moon was formed 4.5 billion years ago, probably due to collision of a protoplanets the size of Mars (called Theia by astronomers). Astronomers call this The Big Twack Theory or The Big Whack Theory.
Theia Collide with Earth
When Theia collide with earth: the first thing is this collision is not had on, in fact it is on our side.
In this, the first thing is you are seeing this collision on an angle and the guess is our moon was formed in a few hours. If you see this picture, you can see a lot of material the idea is 90% of Theia’s material fell down back on the earth. But can we find this material of Theia which fell on earth? Geologists think that they have found that material. How?
How Theia Material Found?
Again, through these seismic waves. 50 years ago, scientists discovered two big structure inside the Earth. The name one of it Tuzo in honor of a Canadian geophysicist Tuzo Wilson. This is below West Africa. The other is below the Pacific Ocean whose name is Jason. He is a pioneer is plate tectonics Jason Morgan. He is an American geologist in whose honor this was given.
These two pieces or these two structure Tuzo and Janson are 2900 km below the surface and they are between the mantle and outer core of our earth. It is a big about the size of a continent and can be seen extending several hundred kilometer above the core.
But recently a new study has been published in journal ‘Nature’ in which they found through computer simulations that probably these two big structure Tuzo and Janson are a result of that Theia and the assumption is this material of Theia is rich in iron compared to the crust of our earth and so it was dense material. After the collision with earth during moon formation when this Theia material reached earth because it was dense it sinked and because of the convection in our mantle (due to which we have lava and volcanic mountains).
This material kept on coming upwards and eventually this iron rich material of Theia accumulated and these two structures Tuzo and Jason or probably made of the material of Theia.
One good prediction is that if you check the material of Tuzo and Janson, it will be more iron rich (relatively) compared to the earth’s crust or the earth’s mantle. This is cool that astronomers or scientists (most are geologists) can, Through simulation, find out what type of events took place 4.5 billion years ago.
Magnetic Field on Mars?
Before leaving let me tell you that we found out about the interior of earth, but this technique has now been applied on Mars also. A lender named ‘InSight’ had reached Mars in 2017 and kept working there till 2022. Its work was only to find out about quack on Mars. it discovered many Marsquakes and let me say that Marsquake have less strength compared to earthquakes but still we can know about the structure and InSight found out that Mars does not have a solid core in its Center And probably this the reason magnetic field are not present on Mars. This has many implications.
What is the connection of solid core and magnetic field, about that we will talk some other time. But let me say one small thing, astronomers knew many things what is the size of the core on Mars etc etc. Then one meteorite crashed on Mars on 18th September 2021, and it was several thousand kilometers away from InSight. Most of the Marsquakes discovered were relatively near and because of the meteorite crash, the seismic waves that were created enabled us to get more refined information about Mars, about the interior of Mars.
Note: Earthquakes destruction for humans and on the other side, this is an amazing thing, that humans used these very earthquakes and through them discovered, what is the structure inside the Earth. And not only this, now we also know that protoplanet Theia due to which our moon was formed, where is its material present inside our earth.
