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NASA Mars Space

MAVEN Ready To Launch Today 55

Posted by samzenpus from the go-to-mars dept.
An anonymous reader writes "Mars seems to have gone from being a warm, wet planet with a liquid core (with magnetic fields strong enough to maintain an atmosphere) to a cooled frozen desert-like surface. By gathering information about the Mars upper atmosphere and its magnetic field scientists hope MAVEN can help explain what happened and where the water went."
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MAVEN Ready To Launch Today More

MAVEN Ready To Launch Today

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  • Oooh (Score:3)

    by binarylarry ( 1338699 ) on Monday November 18, 2013 @11:08AM (#45455077)

    I wonder if this is in central?

  • Pretty easy to speculate... (Score:1, Interesting)

    by Anonymous Coward

    ... and this IS slashdot, after all.

    I think Mars, being small, ran out of natural radio-decay heat sources in its crust and core. Not having enough mass, or enough tectonic activity to churn things up and generate heat, the core solidified, the magnetic field went away, and solar radiation finished them off.

    • Re: (Score:2, Informative)

      by Anonymous Coward
      I suspect you mean the necessary mass to retain that heat. The radioactive decay present in the core would continue at the same rate it does on earth ... it's just that it would have started with less, and would still to this day have less. There will be radioactive decay till the end of time (or close enough), if there were radioactive elements present to start with.

      • Re:Pretty easy to speculate... (Score:5, Interesting)

        by ShanghaiBill ( 739463 ) on Monday November 18, 2013 @11:42AM (#45455363)

        The radioactive decay present in the core would continue at the same rate it does on earth ... it's just that it would have started with less, and would still to this day have less.

        But Mars probably started with less radioactive material. The density of Earth is 5.5 kg/l. The density of Mars is 3.9 kg/l. So something in the early solar system caused more dense elements to end up on Earth rather than Mars. Most geothermal heat is caused by the decay of Thorium. Thorium is very dense, and is probably present in significantly higher concentrations on Earth, compared to Mars.

        • Re: (Score:1)

          by Anonymous Coward

          That would be the large, moon-like object that impacted and gave us our iron core, with sufficient mass and spin to impart a magnetic field. Current speculation is that the mass is the primary factor in Earth retaining it's atmosphere and Mars losing it's, not the magnetic field as has been previously thought.

        • Re: (Score:3, Informative)

          by olsmeister ( 1488789 )
          There is a theory that early in the Earth's history it was struck [wikipedia.org] by a Mars-sized body, blasting off a large portion of the crust and mantle (incidentally forming the moon) and leaving behind a relatively large metal-rich core.

          • The moon has a density of 3.3kg/l, lighter than either Earth or Mars, so that makes sense.

            Can someone please email the MAVEN team, and let them know that Slashdotters have already figured everything out, and they can cancel the launch?

          • Earth already had its iron core at the time of the Moon forming impact. Most of the impactor accreted onto the Earth and the cores of the two bodies merged (Canup and Asphaug, 2001, Nature). A fraction of the silicate crust and mantle of the impactor and target was ejected into orbit. That debris accreted into the Moon. Since it is largely made of the silicate portion of the original bodies, it is depleted in metal, and has a relatively small core.

        • What explains why the most dense elements on Earth can be found on the internet?

        • A few points of clarification.

          1. The major heat-producing elements are all lithophiles, preferentially bounding to silicates. So there's virtually no radioactive decay in the core. It's all in the crust and mantle.

          2. Thorium is an important heat source now due to its long half-life (14 Gy IIRC). But back in the day, Uranium and Potassium-40 were much more abundant, and produced the majority of the radioactive heating.

          3. Assuming the Earth and Mars initially had similar bulk compositions, they would have sim

    • ... and this IS slashdot, after all.

      There's so much that we share that its time we're aware, this is Slashdot after all.

    • I think Mars, being small, ran out of natural radio-decay heat sources in its crust and core. Not having enough mass, or enough tectonic activity to churn things up and generate heat, the core solidified, the magnetic field went away, and solar radiation finished them off.

      Curiousity recently found a (relative) boatload of frozen water all over, in the soil, just under the surface. I forget what the estimate was but it was something like 7 liters per cubic meter of soil... which is quite a lot, really. (Granted, a cubic meter is a lot of soil but 7 liters is nothing to sneeze at either.)

  • Live Coverage (Score:5, Informative)

    by Ashenkase ( 2008188 ) on Monday November 18, 2013 @11:21AM (#45455159)

    http://spaceflightnow.com/atlas/av038/status.html

    Any other links out there? I generally use Spaceflight Now for the text updats along with the live feed.

  • Not Magnetic Fields (Score:3)

    by camperdave ( 969942 ) on Monday November 18, 2013 @11:31AM (#45455269) Journal
    Magnetic fields are not what holds an atmosphere. Gravity does. Consider Venus. It does not have a magnetic field, yet it has quite a thick atmosphere.

  • Is anyone else taking odds... on whether or not they're going to smack the thing into the Indian probe?

  • Anyone else wondering (Score:1)

    by Anonymous Coward

    What was used to _build_ maven?

  • ....cooled frozen-dessert like surface.....

  • Just like my ex-wife.

  • Should we all talk? (Score:3)

    by Nexus7 ( 2919 ) on Monday November 18, 2013 @12:35PM (#45455819)

    MAVEN's going to arrive around the same time as Mangalyaan, assuming both do arrive. The arrival rate at Mars is pretty low (with NASA having the best one, 70%). It's going to study the upper atmosphere, just as Mangalyaan plans to. This cost NASA $670 M, at a time when Congress is cutting everything like it (Comments about republicans and science withheld - Editor).

    I really hope these guys talk. I understand descriptions in popular media blur the details, but there seems to be a lot over overlap here.

    • Re:Should we all talk? (Score:4, Insightful)

      by Antipater ( 2053064 ) on Monday November 18, 2013 @12:48PM (#45455921)
      The article from NBC [nbcnews.com] mentions that there will be some cooperation.

      The teams for Maven and Mangalyaan plan to collaborate in their studies of the Red Planet's atmosphere. For instance, there's been some evidence that methane is being released into the Martian atmosphere, which could hint at biological activity. Curiosity hasn't detected any methane at the surface, and Maven won't be measuring methane because that doesn't mesh with the mission's scientific goals. But Mangalyaan can take a closer look at the methane question, and its results could add to Maven's models.

    • Cheap if you ask me. That's about what it cost to delelop the 'affordable health care' web site.

  • Thought we were talking about a Java build (Score:3)

    by sproketboy ( 608031 ) on Monday November 18, 2013 @01:06PM (#45456057)

    It is newsworthy that you can get a build to work with Maven. /s

  • NASA will be launching another rocket, a Minotaur, from Wallops Island: http://www.nasa.gov/content/air-force-minotaur-rocket-launching-from-virginia-november-19/ [nasa.gov] I will be photographing the night launch and should have some good pics up. Check my journal for them, there may also be Air Force interviews after the launch, I'll see if I can get some words in as well

  • "... with magnetic fields strong enough to maintain an atmosphere"

    I guess this concept works best with an atmosphere that consists of magnetic nitrogen, magnetic oxygen, a dash of magnetic carbon dioxide and so on.

    Sounds fancier than poor old gravity maintaining a boring non-magnetic atmosphere.

    "Let's sing another song, boys. This one has grown old and bitter."
    - Bob Dylan

  • Where are they? "hoyven Maven"

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