Thread: A more massive mars

I am wondering something and its been on my mind for a while.
Lets say we raised the desnity of mars to 6 g cm/3 and left its radius at 53% Earths radius.
What would these new changes cause? Im wondering the effects on the core, atmosphere, mountains, volcanoes and overall environment.
Could there be a thicker atmosphere?
Could the core be molten with this increase in density?
What would happen to the volcanoes and the way magma flows due to less gravity?
Would there be a size limit to the mountains on its surface?

I understand this would be a dramatic increase in density and mass and thats why im asking.

Thanks

The consequences would depend to a great extent on how you achieved that density increase. Actually I can't see how you can do it other than by massively increasing the core size.

With a reduced mantle then convection and consequent vulcanicity might well be reduced. You said reduced gravity, but I guess that was a mis-statement. The increasef gravity would help retain an atmosphere and make lava flows thicker, but not as long. Olympus Mons would be smaller. Any bigger and the crust would sag under it. More saggin in more gravity.

Those are off the top of my head observations. If I think about it I might change 1/3 of them.

I would think if the core was bigger and had enough radioactive isotopes then it would be molten? I would also have thought that a molten core would produce more volcanic activity through incresed heat not less. Yeah i did mean increased gravity ooops.

Most radioactive elements are not siderophiles, but lithophiles. i.e. they are concentrated in the rocky portions of the planet, not the iron core.

The core is not going to be any hotter because it is iron. The principal heat is a consequence of gravitational collapse. Core formation also generates heat, but overall the more conductive core will dispel heat faster, so although intial vulcanicity may be greater, it will be more shortlived.

Remember, these really are guesses - I hope they are intelligent guesses, but guesses nonetheless.

So even if volcanic activity was reduced do you think it would be more active than today? I say this because there is no eveidence of an eruption exept for millions of years ago. Yes i would think it has a thicker atmosphere because of more gravity no that i think about it.

I am suggesting that the activity might be greater initially, but that it would be over more quickly. You say, correctly, that there seems to have been no eruptions for millions of years on Mars. However there is evidence for possible eruptions within the last twenty million years and that, in geological terms, is no time at all. The methane content detected in the atmosphere could also point to ongoing activity rather than biological sources, or a recent comet strike.

Yeah the whole methane thing from volcanic vents or outgassing makes sense way more sense. If you wanted to have mars be more volcanically active longer i would lower the density but not lower it to the density it is now. I would say 5.48 g cm/3 would be fine.

Well, to give some limits, the universe is ~13.7 billion years old, the solar system (and earth) ~4.5 billion years old. The first multicellular life on earth was aboiut 1 billion years ago, and the first animal life about 600,000 years.

Wayne, did you post that in the wrong thread? If not, how is it relevant to the discussion?

Oops, yeah, you're right!!