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What Happened To the Martian Ocean and Magnetic Field? (theatlantic.com)

schwit1 writes with this story at The Atlantic that explores what may have destroyed the Martian atmosphere and ocean. The question of whether there is life on Mars is woven into a much larger thatch of mysteries. Among them: What happened to the ancient ocean that once covered a quarter of the planet's surface? And, relatedly, what made Mars's magnetosphere fade away? Why did a planet that may have looked something like Earth turn into a dry red husk? “We see magnetized rocks on the Mars surface,” said Bruce Banerdt, the principal investigator of the InSight mission to Mars, which is set to launch in March. “And so we know Mars had a magnetic field at one time, but it doesn't today. We would like to know the history—when that magnetic field started, when it may have shut down.”

2 of 142 comments (clear)

  1. This is basic planetary physics.. by Lumpy · · Score: 5, Informative

    Mars has no Magnetic field because it's core cooled and is no longer a active moving iron mass. it cooled faster as it has very little radioactive isotopes and being further away from the sun it has less energy pounding it to slow the cooling.

    http://www.scientificamerican....

    Plus we had an event late after the formation of the planets in the solar system that also added a buttload of energy, when the moon was formed from a planetary sized impact.

    --
    Do not look at laser with remaining good eye.
  2. Re:This is basic planetary physics.. by Anonymous Coward · · Score: 5, Interesting

    It is thought to be related to the disappearance of the Martian atmosphere. The magnetic poles divert the solar wind towards themselves, and prevents it from hitting most of the planet. When the magnetism disappears, the solar wind blows the atmosphere away.

    When the atmosphere disappears, the pressure is reduced, and with it the boiling point of water, until water can only have two states - ice and gas form. The water that doesn't turn into ice goes the same way as the rest of the atmosphere.