Martian Core Composition: Is it Solid or Liquid? My Theory on Volcanic Activity

[willstaruss22]

Some say its liquid some say its solid, here's what i think. While i believe about 60-80% is solid, i believe the rest is similar to Earth's mantle in a sticky molten state. Due to its very slow movemet it would not generate a global magnetic field. It would however generate enough heat to the surface to produce volcanic activity every 100,000- 1 million years or so. Due to the size and the rate of cooling i came to this. Any thoughts on this?

 

[Simon Bridge]

The immediate thought of any sensible physicist - particularly those with an interest in planetary physics - will be to wonder how you are supporting these thoughts. What is the scientific evidence that leads you to these ideas? How did you arrive at the 60-80% figure?

 

[willstaruss22]

The fact its 1/2 the size of Earth and its 4.6 billion year old history tells it can't be like Earth's core because its smaller and it can't be completely solid because 4.6 billion years isn't enough time to completely solidify a core 100% so I am giving a rough estimate. Plus the minimal volcanic activity, i read they found evidence of a lava flow that occurred 2 million years ago and they had a marsquake last year so it must be active in some way or another. But its not as active as Earth for obvious reasons like its smaller an less dense so there isn't enough heat to power that much volcanism. Thats all.

 

[willstaruss22]

Plus if it were liquid like Earth's it would have much more heat for the mantle and volcanism.

 

[Simon Bridge]

That is actually enough time - however, more recent data suggest an FeS core making it more likely to be at least gooey. A lot depends on the chemistry.

You may like to see:
http://cars9.uchicago.edu/gsecars/LVP/publication/News/X-rays%20reveal%20secrets%20of%20Mars'%20core.htm

I take it the 60-80% figure was just a wild guess?

 

[willstaruss22]

Yep a total guess, based on lack of magnetic field.

 

[Simon Bridge]

There is a saying along the lines of "67.5% of statistics are made up on the spot" :)
Not a good idea around scientists - they are all used to peer reviewed articles.

You'll just get questions like "What was it about the lack of magnetic fields that suggested that particular ratio as a worthwhile guess?" :) On the other hand, it is totally OK to not know.

 

[d3mm]

http://cars9.uchicago.edu/gsecars/LVP/publication/News/X-rays%20reveal%20secrets%20of%20Mars'%20core.htm

In the diagram, they call Mars "nearest neighbour". We had an argument in another thread about that! Similarity to Earth != distance from earth.

It's no surprise the journalists get it wrong when the sources they copy from are ambiguous. Should we write to them?

 

[Simon Bridge]

It's an ambiguous description anyway - the planet physically closest to the Earth changes over time. For all you know they will quote you the parable of the good Samaritan.