Do we have some estimates as to how warm Mar's core is?

[willpittenger]

I figure it might be warm enough to have some molten rock even if that is not enough (especially in iron content) to start the dynamo effect that would create a global magnetic field. Since the field is not present, either iron is missing from the core or it is cold enough to limit the molten part.<br /><br />Given the size of select Martian features like Olympus Mons, the Tharsis Bulge, and a certain canyon; I think we can eliminate the possibility of tectonic plates. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[qso1]

An excellent question, I wish I had the answer but right now I don't and I'm not sure what the state of knowledge on Mars core is within the astronomical community. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[yevaud]

Current thought is that Mars' core is largely inactive, in part due to the lack of tectonics and vulcanism, as well as it's mostly absent geomagnetic field.<br /><br />As to why, thoughts on that range from a lack of sufficient radioactive material present with which to keep the core molten through the fact that Mars differentiated so fast comparative to Earth.<br /><br />Of course, the simplest answer of all is, "we just don't know yet." <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[centsworth_II]

<font color="yellow">"we just don't know yet."</font><br /><br />What we need to start finding out is a network of seismometers on Mars. Then just wait for marsquakes -- if they exist -- or meteor impacts. Or provide an artificial percussion. Analysis of the data will start to give a look into the cross section of Mars.<br /><br />There is great interest in such a mission, but it has yet to get to the head of the line of missions waiting to get to Mars.<br /> <div class="Discussion_UserSignature"> </div>

 

[willpittenger]

From what I remember reading years ago, the Viking landers were equipped with seismometers. However, they were mounted in the body of the lander rather than in direct contact with the soil. Every time the wind caused the lander to shift on its legs (which had to move during landing), the seismometers registered a quake. That was all the time.<br /><br />As for the "artificial percussion," some lunar lander ascent stages where deliberately crashed into the moon. Some Saturn V 3rd stages were also crashed. Those were probably intended to create moonquakes. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[nexium]

My guess is the center of Mars is 500 degrees c = 932 f and the temperature one kilometer below the surface averages 0 degrees c = 32 degrees f, so liquid water is found a few kilometers below the surface, and steam and other volitiles, hundreds of kilometers below the surface of Mars. Admittedly this may all be wishful thinking. Neil

 

[agnau]

I'm certain that I read somewhere a way of determining temperature from pressure and volume. We can get the pressure on the core from the mass and gravity of mars while the volume can be found from the size. Let me see....<br />For a gas body it would be PV=nRT (reading from http://www.shodor.org/UNChem/advanced/gas/ ) or T = (PV)/(nR)<br /><br />I would expect nR to be proportial to the mass of the body based on R = volume/moles of gas. I don't know how to determine the correct nR value for a solid such as a planet. This is also presuming no heat generated by rotation, radiation, solar activity (winds/plumes/flares), or magnetic induction.<br /><br />Reading from another site (at http://www.ccl.net/cca/documents/dyoung/topics-orig/eq_state.html ) gives the following equation for solids:<br /><br />Vm = Vmo ( 1 + A T + B T^2 )<br />with: Vm = molar volume; Vmo = molar volume at 0 degrees C; T = temperature; A, B = positive empirical constants<br />-(Vm/Vmo) - 1 + A T + BT^2 = 0.<br />Solve for T using the quadratic formula....<br />T=(-A +-sqrt(A^2-4B(Vm/Vmo))/2B)<br />The only real question here is what are Vm/Vmo. B, and A.<br />Vm can be found by average of what we suspect Mars to be composed of and then Vmo can be determined from that. The constants A and B are beyond me where to begin but I would suspect they have to do with the surface pressure (B) and the core pressure (A).<br /><br />If we compare the gas and solid versions of the relation we do see that it should be possible to say:<br /><br />(PV)/(nR) = (-A +-sqrt(A^2-4B(Vm/Vmo))/2B)<br /><br />Check my math if you would please. <br /><br />You can get some useful valus from http://www.solarviews.com/eng/mars.htm where I see that:<br /><br />Mean surface temperature = -63°C<br />Mass (Earth =