posted on Oct, 13 2010 @ 01:46 AM
Originally posted by TrueAmerican
Here is a fascinating and well written documentary all about Mars, mars missions, and evidence pointing to a huge asteroid as the cause for the
eventual disappearance of its magnetic field.
It's not well written, it doesn't even provide any evidence.
It mentions "alternate theories" about why the magnetic field may have disappeared but doesn't even say what they are, that's a sign of a poorly
I don't think anyone doubts that early Earth and early Mars were both hit by giant asteroids, so if it was done by impacts, why did the impacts only
eradicate the magnetic field on Mars and not on Earth? No explanation of this discrepancy is given, and the alternate theories DO explain why Earth
still has a magnetic field and Mars doesn't.
For example this article makes much more sense:
Did an asteroid kill Mars' magnetic field?
"Earth probably took the same kind of punishment," Roberts said. "But it's primarily a function of size. Earth has more than 10 times more heat
than Mars, and much more vigorous convection."
I say both Earth and Mars were hit with many impactors, Mars lost most of its magnetic field far more rapidly than the Earth did. But I also submit
the same thing would have happened even if both planets had been spared the asteroid impacts. Mars still would have lost its magnetic field for
exactly the same reason, it's a matter of size. The mass to surface area of Mars is much different resulting in more rapid cooling.
In fact I would even go so far as to say the opposite of this video's claim might be true, that asteroid impacts might have actually extended the time
that the Martian magnetic field existed versus a no impact scenario. Why? Because a molten core is needed to sustain a strong magnetic field, and the
additional heat energy from impactors could have served to actually keep more of the core molten for a LONGER period of time than a no-impact
Someday we will be able to study the geological evidence on Mars more closely and will be able to make more definitive assessments about why Mars lost
much of its magnetic field and thus its atmosphere more quickly than Earth. My prediction is that when the data is collected and the analysis is
complete, the answer will be just what I quoted above, the main reason that earth kept it's atmosphere and magnetic field longer is primarily because
it's bigger. So the talk about asteroid impacts is just noise from that perspective, since asteroids impacted both planets.
edit on 13-10-2010
by Arbitrageur because: fix typo