Mystery of Mars Missing Magnetic Field -Was It Destroyed by Asteroid Impact?

If you've seen The Core then you that the only thing between us and instant space-death is a magnetic field.  You also know that's the only thing that's even heard of real science in the entire movie, but it's a pretty important one - and could explain why the otherwise eminently habitable Mars is such a barren wasteland.  Scientists think the Martian magnetic field might have been hammered into submission by strikes from space. (The image above shows the the Syria, Sinai, and Solis Planum impact areas).

Planetary magnetic fields are created by massive molten metal currents within the planet's core.  A flowing current creates a magnetic field, even when the current is massive volumes of charged liquid metal moving under the influence of temperature gradients (convection) - in fact, especially then.  But magnetic analysis of Martian sites by Berkeley researchers show that the red planet's protective field was switched off half a billion years ago, and now some scientists say they know why.

John Hopkins University scientists have calculated that a period of massive asteroid impacts, known to have happened around the same time, could not only have massively impacted on the surface Deep Impact-style (with all the atmospheric alteration and great-big-crater-making that entails) but added enough energy to the planet to heat up the outer layers of the planet.

Without the huge temperature difference between the core and mantle, the mega-magnetic dynamo convection currents would be switched off - and unable to start up again when things cooled down.  Remember, planetary core behavior is still carrying on from when the planets first formed - as far as they're concerned the whole "crust" thing and all life as we know it is just a cooling scum on the surface.  If you break something from back then you just don't have the juice to start it up again.

Without the magnetic field Mars is defenseless against the radiation that constantly pours in from space (never mind the Fantastic Four, the only superpower cosmic rays'll give you is decomposition).  Earth is thought to have survived the same space-bombing because of our superior size, with our dynamo maybe stuttering a little but - very importantly - not stopping.

As you can maybe tell by the fact you exist.

Posted by Luke McKinney.

Did Mars' Magnetic Field End With A Bang Or A Whimper?

Comments

[Brian]

Actually there are a number of pieces of real science in the movie although admittedly most of the stuff is just a bunch of crap.

[huh]

Learn to use punctuations properly. this article is a pain to read

[Cris]

Interesting article but, honestly, you either need to proofread before you post or learn to structure your sentences a little better.

Regardless, thank you for the article.

[stephen miller]

The asteroid rain on Mars may have resulted from the destruction of a planet between Mars and Jupiter which has left the 'asteroid belt' there. Meteorites originating from the asteroid belt are either nickel-iron or stony. Nickel-iron ones likely came from the planet's core (as only in a planet would this heavy material gravitate to the center and cohere in mass) while the 'stony' meteorites are from the destroyed planet's rocky crust.
Large quantities of Martian material, as well as debris from the destroyed planet, would have also reached Earth, and the time-frame corresponds roughly to the Cambrian explosion of life-forms here.

[Dave]

"Without the huge temperature difference between the core and mantle, the mega-magnetic dynamo convection currents would be switched off ......"

Why?

[Jhonson]

But magnetic analysis of Martian sites by Berkeley researchers show that the red planet's protective field was switched off half a billion years ago, and now some scientists say they know why.