Posted by
michael
on from the mars-doesn't-want-to-go-on-the-cart dept.
mikef2501 writes "Science Daily News reports
that results from three years of radio tracking by the Mars Global Surveyor spacecraft indicate that the core of Mars may not be geologically dead after all -- it may still contain at least partially molten iron (original news release found here)."
What makes a core hot?
by
stefanlasiewski
·
· Score: 2, Interesting
Ok, here's a question for you geology geeks. What makes a planet core hot?
I've heard some people say it's heat caused by friction resulting from gravitational pressure (I think this is what they taught me in school), but I've had several Geology Doctorates say that the heat actually results from radioactive decay (Similar to radioactive decay in some granite).
So, which is it? Help my geoneophyteness!
-- "Can of worms? The can is open... the worms are everywhere."
Magnetic field?
by
General+Wesc
·
· Score: 2, Interesting
Wouldn't a molten iron core (rather than solid) mean the magnetic field is stronger? I recall that Jupiter has an extremely strong magnetic field because of the liquid hydrogen core. It seems like a half-decent measurement of Mars' magnetic field should give us a decent idea of what its core is like.
Re:Magnetic field?
by
barakn
·
· Score: 2, Interesting
Hmmmm... magnetic fields generated by liquid core dymanos are generally dipoles (except when they are flipping over). Mars' magnetic field is extremely weak in the northern hemisphere (blasted off by an enormous collision). In the south it is patchy: in some areas it comes in stripes of opposing polarity. This suggests it is remanent magnetism frozen in place when the rocks first formed. There must have been a reversing dipole field at one time, and each stripe of rock formed between field reversals.
The set of equations used in magnetohydrodynamics is so complicated we don't even understand the Earth's magnetic field very well. Rotation, turbulence, magnetism frozen in to the solid core, the chemical evolution of the liquid iron (sulphur or no sulphur?) and a myriad other factors all play a part.
My personal guess is that Mars' core doesn't generate much of a field because it is small and so doesn't have a large moment of inertia. But ha! What do I know?
-- "I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show
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Ok, here's a question for you geology geeks. What makes a planet core hot?
I've heard some people say it's heat caused by friction resulting from gravitational pressure (I think this is what they taught me in school), but I've had several Geology Doctorates say that the heat actually results from radioactive decay (Similar to radioactive decay in some granite).
So, which is it? Help my geoneophyteness!
"Can of worms? The can is open... the worms are everywhere."
Wouldn't a molten iron core (rather than solid) mean the magnetic field is stronger? I recall that Jupiter has an extremely strong magnetic field because of the liquid hydrogen core. It seems like a half-decent measurement of Mars' magnetic field should give us a decent idea of what its core is like.