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Mars Science

Radar Map of Buried Mars Layers Confirms Climate Cycles 114

Posted by Soulskill
from the dust-and-sand-need-seasons-too dept.
Matt_dk writes "A radar instrument on the Mars Reconnaissance Orbiter has essentially looked below the surface of the Red Planet's north-polar ice cap, and found data to confirm theoretical models of Martian climate swings during the past few million years. The new, three-dimensional map using 358 radar observations provides a cross-sectional view of the north-polar layered deposits. 'The radar has been giving us spectacular results,' said Jeffrey Plaut of JPL, a member of the science team for the Shallow Radar instrument. 'We have mapped continuous underground layers in three dimensions across a vast area.'"
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Radar Map of Buried Mars Layers Confirms Climate Cycles

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  • Old news (Score:2, Funny)

    by b0ttle (1332811)
    Douglas Quaid knew it already.
  • by j-turkey (187775) on Wednesday September 23, 2009 @01:11PM (#29517823) Homepage
    Yes, but does it coincide with the industrial revolution? Does it fit the hockey stick model?
  • I can't wait until Mars warms up and gets some moisture. I'm already flipping through astronomy stores for telescopes that will let me watch the penguins from here.

  • by Anonymous Coward
    I better post this as anonymous, before the true believers mod me into oblivion. But if we see evidence of climate change on a planet that barely even has an atmosphere to speak of, maybe we're not giving the power our own sun enough scrutiny in the global warming debate.
    • by mbone (558574) on Wednesday September 23, 2009 @01:52PM (#29518603)

      No true believers are required.

      Unlike the Earth (which has a big Moon to anchor things), Mars has huge variations [imcce.fr] in insolation due to its obliquity and eccentricity cycles. These oscillations drive large variations in climate, which causes the cool layering [arizona.edu] in the Martian Polar Caps - the so called North Polar Layered Deposits [arizona.edu]. There are lots [arizona.edu] of cool pictures [arizona.edu] of these layers.

      While it is true that both the Earth and Mars would exhibit climate changes if the solar luminosity changed, so far I have not heard of any evidence requiring this from Mars. Mars's internal and orbital dynamics are quite enough to keep the climate modelers busy.

      • Re: (Score:1, Insightful)

        by Jhon (241832)

        And does that explain the warming noticed on Jupiter, Titan, Pluto and various asteroids to name a few?

        Not saying there is no anthropogenic impact on climate -- I'm just saying it's total impact may be over stated and contributing to an already occurring phenomenon.

        I certainly HOPE we have the ability to effect climate as much as claim. Living in a hot, jungle world or a cold ice world have little appeal to me. And since those climates have occurred in our past, we can assume they will most likely recur a

        • Re: (Score:3, Informative)

          by bunratty (545641)

          And does that explain the warming noticed on Jupiter, Titan, Pluto and various asteroids to name a few?

          There are several hypotheses regarding the warming observed on Mars and Pluto [newscientist.com].

        • Re: (Score:1, Flamebait)

          by geekoid (135745)

          Or you can, you know, do math.

          Apply the inverse sqr law to the rise in temperature and how it would impact the temperature change on ifferent planets.

          Also not if it was the sun it would be happening to ALL bodies in the solar system, and it is not.

          Next.

          Yes, we are experience and increased global changed due to the millions of tons of CO2 we spew into the air every day.

          • by Jhon (241832)

            Lets assume you are correct. Who's to say a warmer earth is bad? It wasn't long ago we were told we were heading in to a new ice age. Climate cycles actually suggest we are (were) heading down that path. Wouldn't we WANT to warm the earth?

            Ice age aside, wouldn't an increased crop growth durations help battle famine? Who's to say the effects will have a negative impact? Lets study the impact rather than demand we do stuff that will destroy not just the developed worlds economy, but potentially starve mi

        • by mbone (558574) on Wednesday September 23, 2009 @04:47PM (#29521597)

          First, you are aware that the solar output (Solar Constant) has been measured since the 1970's ? There is no need to look at distant worlds to see if it is changing - it varies around at about the 0.1 % level [nasa.gov].

          Second, I would not put any weight on observations of any body we have not observed for more than one orbit - and that includes Pluto and (for climate) Titan. These are not simple bodies.

          The general cause of Pluto's warming is well known - a highly elliptical orbit, and it's near (just past) perigee, where it outgases Methane into the atmosphere. That's one of the motivations behind Pluto Express (to get there while there is still a bigger atmosphere). It is staying warm past perigee, but we have no idea if that is normal or not. Similarly, Titan is passing through the equinox (just as we are here on Earth), and that is causing seasonal change. We know that's happening; we have no idea if what we are seeing is normal or not.

          Jupiter is so different from the Earth or Mars that I wouldn't use it as an analogy for anything terrestrial, good or bad. (For example, it generates more heat internally than it gets from the Sun.) Having said that, I had not heard of any warming reported there, so a link would be welcomed.

          • ...and it's near (just past) perigee ...

            Minor quibble: if you're talking about orbital distance from the sun, I think you may actually mean perihelion [google.com] or periapsis [google.com].

          • by Tuoqui (1091447)

            First, you are aware that the solar output (Solar Constant) has been measured since the 1970's ? There is no need to look at distant worlds to see if it is changing - it varies around at about the 0.1 % level.

            Well 0.1% can vary quite a bit too... I mean just looking at percentages the bigger something is the more it will vary by.

            For Example
            0.1% of 1000 = 1
            0.1% of 1,000,000 = 10,000

            The former is pretty small change, the latter is a potentially huge change.

  • by MarkPNeyer (729607) on Wednesday September 23, 2009 @01:29PM (#29518165)

    The existence of natural climate change on Mars does not rule out anthropogenic climate change on Earth. The shifts in temperature on Mars happened over periods of hundreds of thousands of years. The climate change we're observing on earth has happened in less than 100 years. There's a huge difference between the two phenomena.

    • ... doesn't even particularly speak to whether or not there can also be anthropogenic climate change on Earth. Natural mechanisms don't preclude human influence.

    • by bonch (38532)

      Climate changes have been happening on Earth for far longer than 100 years...

    • Re: (Score:1, Flamebait)

      by smoker2 (750216)

      The climate change we're observing on earth has happened in less than 100 years.

      You're full of shit.

    • by Lars T. (470328)

      The existence of natural climate change on Mars does not rule out anthropogenic climate change on Earth.

      More importantly, The existence of natural climate change on Earth does not rule out anthropogenic climate change on Earth, even if certain people keep claiming just that.

  • by mbone (558574) on Wednesday September 23, 2009 @01:32PM (#29518217)

    While these results are cool, the obliquity cycle was confirmed in 2002, in a paper in Nature, Orbital forcing of the martian polar layered deposits [nature.com] by Jacques Laskar et al., They used pictures of the layering at the edge of the polar caps, not radar, but its basically the same idea, and they showed good correlation with recent obliquity cycles.

    Again, it's cool to see these layers throughout the caps, but I don't think that anyone has doubted the connection with the obliquity / insolation cycles for a while.

    • well... now it's been confirmed again. :)
      • Re: (Score:3, Interesting)

        by mbone (558574)

        Well, I have not the slightest doubt that Nathaniel Putzig and company know all about these earlier results - but, once you get the PR people involved, they always want to say, first, confirmed, etc.

    • How dare you bring an actual scientific response to google! You should, instead, include some of the more responsable slashdot responses:
      1. Did it locate the marsian death camps.
      2. In soviet mars, the climate cycles you.
      3. Imagine a beowulf cluster of these.
      4. Profit

    • by Tablizer (95088)

      "Confirm" is perhaps the wrong word. Each new discovery adds to the strength or the likelihood of a hypothesis, which is never 100% in this business. It's not Boolean.

      • by mbone (558574)

        I agree - most of this is PR, which can be ignored.

        To me, the interesting thing is that these layers is that they do not represent a very long history. From Laskar et al. (2002) [nature.com]

        For the best fit between the radiance profile and the simulated insolation parameters, we obtain an average deposition rate of 0.05 cm yr-1 for the top 250 m of deposits on the ice cap of the north pole of Mars.

        Now, 5 x 10^-4 meters / year means that the top 250 meters represents ~ 500,000 years, and the entire 2 km thick cap represe

  • by Anonymous Coward

    The Council of Elders has declared tomorrow a day of commemoration. K'breel, Speaker for the Council, spake thus:

    "By Gfa'rdmn, a little over half a year ago, our forces celebrated victory [slashdot.org] over the plumb-bob-waving monstrosity from the North, having slowly chilled it to death. The Invader from the Plains sits enmired [spaceflightnow.com] in our sandpit. The Twin by the Crater has begun to stir, but it stood paralyzed by fear for sixty days [marsdaily.com] by the mere sight of the spent husk of a Kinetic Bombardment Force component."

    "So th

  • How do Martians know whether it's the rainy season or dry season?
    • by Nadaka (224565)

      Its the dry season. Rainy season ended a couple million years ago.

      • by jc42 (318812)

        Its the dry season. Rainy season ended a couple million years ago.
        Depends on where you are. Most of the current climate models have the eastern part of North America getting wetter as the temperature rises, while the western part gets drier. The American South just got a week-long dose of that pattern, and there have been lots of news stories about the growing drought in most of the Southwest.

        Yes, it has all happened before, and it'll happen again. OTOH, we are reaching a level of understanding that sugg

        • by Nadaka (224565)

          woosh?

          I was referring to mars. The martians know its the dry season because it has not rained in a few million years.

          • by jc42 (318812)

            Yeah; all them Martians should move to California. They'd have more water than they've ever seen.

            Hmmm ... Maybe they have. Maybe that's why we don't find them on Mars.

            But I wonder how they survive the summer heat? It gets well above the melting point of ice in California in the summer.

  • The polar ice cap is 1 million cubic kilometers of water ice. Martian surface gravity is .375 g. Escape velocity is just over 5 kilometers per second. Summer temps are up to 20C. At 1.5 A.U., solar power is about 1/2 that of Earth per square measure. Mars has two moons ripe for mining.

    Nobody owns it yet.

    • by G33kGuy (1152863)
      It takes 9 months do get there and back, its wintertime temperature is around -100C, it has about 96% less atmosphere, there is absolutely no existent infrastructure, there is very little oxygen in the atmosphere, it has no magnetic field to shield from solar winds, and it sometimes has global dust storms. And nobody owns it yet.
      • by symbolset (646467)

        Antarctica has wintertime temps below -89C, there is no existent infrastructure. But it doesn't have a location for a base with a planetary escape velocity of 186MPH starting from a base less than .4 G's.

        Water is liquified oxygen, with a little hydrogen mixed in. Ice makes a nice airtight structure, and it's opaque to solar wind.

        Mars is also right next to the asteroid belt. It's a natural base for the people who will build our interstellar ships.

        The moon has water too apparently and getting free of it

  • by Alarindris (1253418) on Wednesday September 23, 2009 @06:16PM (#29522953)
    I read that as

    Radar Map of Buried Mars Lawyers Confirms Climate Cycles
  • Jumping in and blithering about how this disproves global warming.

    Guys, we have had climate cycles and ice ages here on Earth as well. They're normal. Global warming is not the same thing.

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