Tech | March 23, 2011 | 20 comments

How Vital Is a Planet's Magnetic Field? New Debate Rises

source: http://www.space.com/11187-earth-magnetic-field-solar-wind.html

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Schnookums
Our nearest planetary neighbors, Mars and Venus, have no oceans or lakes or rivers. Some researchers have speculated that they were blown dry by the solar wind, and that our Earth escaped this fate because its strong magnetic field deflects the wind. However, a debate has arisen over whether a magnetic field is any kind of shield at all.

The controversy stems from recent observations that show Mars and Venus are losing oxygen ions from their atmospheres into space at about the same rate as Earth. This came as something of a surprise, since only Earth has a strong dipolar magnetic field that can prevent solar wind particles from slamming into the upper atmosphere and directly stripping away ions.

"My opinion is that the magnetic shield hypothesis is unproven," said Robert Strangeway from UCLA. "There's nothing in the contemporary data to warrant invoking magnetic fields."

Each of the three planets is losing roughly a ton of atmosphere to space every hour. Some of this lost material was originally in the form of water, so this begs the question: How did the planets end up with vastly different quantities of water if they are all "leaking" to space at similar rates?

"The problem is in taking today's rates and trying to guess what was happening billions of years ago," explained Janet Luhmann of the University of California, Berkeley. She believes Earth's magnetic field could have made the difference in the past when the solar wind was presumably stronger.

"People aren't putting all the cards on the table," Luhmann said. "We can't say that magnetic fields are unimportant from the current data."

Both Luhmann and Strangeway agree that sorting out what makes one planet wet while another is dry will require more data on how the atmospheric loss depends on the sun's output.

Buffeting in the solar breeze

The main driver of ion escape from planetary atmospheres is the solar wind, which is a high-speed outflow from the sun consisting mostly of protons and electrons. Because these particles carry a charge, their paths bend when they encounter a magnetic field.

For non-magnetized Mars and Venus, the solar wind basically barrels straight into the upper atmosphere and scoops up ions and carries them into space. Warth's magnetic field provides a barrier to the solar wind, called the magnetosphere, but ions still get stripped away through a circuitous route.

Essentially, the solar wind interacting with the Earth's magnetic field transfers some of its energy into the upper atmosphere in the polar regions. The auroras that are visible at high latitudes are one manifestation of this transfer. But it also heats up atmospheric ions enough that they escape up out of the poles, forming Earth's "polar ion outflows."

"The magnetic field is an obstacle to the solar wind, but it is also a funnel," Strangeway says. The effect of the solar wind on Earth is less uniform than on Mars and Venus, but apparently the net loss rate is about the same.

Strangeway explains this in terms of momentum. The solar wind loses some of its momentum when it runs into any planet. [Photos: Auroras Dazzle Northern Observers]

Basic physics suggests that this momentum has to go somewhere, and according to Strangeway, it goes into the polar region atmosphere to energize ions there to velocities sufficient to escape Earth’s gravity. The presence of a magnetic field changes the mechanism for this momentum transfer, but the end result is similar.

At least, that seems to be the case now........

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20 comments // How Vital Is a Planet's Magnetic Field? New Debate Rises

  • S3th
    • 0
      S3th  

    • In other words, we are looking at a two dimensional representation of our magnetic field, with the solar wind hitting it and the solar radiation deflected, with a little being taken in at the poles creating the northern and southern lights...But, what isn't illustrated, even though they know the magnetosphere always keeps the bow towards the sun. But, what isn't easily visualized, especially with our current, DUMBED DOWN EDUCATION SYSTEM, is that our SUN is moving through the galaxy, with us trailing along, constantly orbiting the sun, but along a completely new path, constantly. Our 2D model as we have been given to understand our solar system is completely flawed!

    • 11 months ago
  • S3th
    • 0
      S3th  
    • Image

    • Part of the problem is in our science itself. Whenever you try to isolate a system, instead of leaving it open, as one should, the data you get is FLAWED. Watch this video...It will leave you breathless with new insights into all this stuff, as you see a much more expansive view of Earth, the Sun, and how we actually move through our solar system.

      ENJOY!

      http://www.youtube.com/watch?v=wVskWr2NW2Q

    • 11 months ago
  • bailey78
    • 0
      bailey78  

    • Ya know I'm not sure what part of My life it plays But lets not go fucking with to much. Ok? They have this saying at this place I go sometimes. if it ain't broke don't fix it. It took me a long time to figure out how simple that truely is. Why don't they go learn what makes Grass grow then plant a lot of grass or something.

    • 1 year ago
  • Johnny_Los_Angeles
    • 0
      Johnny_Los_Angeles  

    • one simple obvious fact blows the assumption out of the "water" right away... Earth is 3 times as big as Mars and that alone would mean our atmosphere would last longer than Mars did anyway!

    • 1 year ago
  • s_peak
    • 0
      s_peak  
    • Johnny_Los_Angeles:

      Our oxygen is also replenished by plants... but we are burning the candle at both ends by chopping down all the forests and replacing plants with pavement.

      Also take into account the amount of finite material we waste on things like touch screens, barbie dolls and Escalades... and it becomes apparent that we're eating ourselves out of house and home. The whole of "civilized" human history has been the story of us taking energy out of the system and then putting it in places it doesn't go or not replacing it at all. What does this mean? Not to be alarmist... But eventually it means full ecosystem collapse. And a few thousand years later, our planet will die (or maybe only we will) and look just like mars. So there's that to look forward to.

    • 1 year ago
  • bailey78
    • 0
      bailey78  
    • s_peak:

      You like many people seem to think the Planet is in danger of dieing. When in fact it is some of the life forms on the Planet that are in danger of dieing off. Humans being one of them. There will always be some form of life on Earth so long as there is water. Even bad water will grow something.

    • 1 year ago
  • s_peak
    • +1
      s_peak  
    • bailey78:

      I actually already edited my comment to reflect that... so I do agree. Eventually things will fall back into place when all of us are gone. That is the nature of... uh... nature. :P

    • 1 year ago
  • XasthurNortt
    • XasthurNortt  
    • This comment was removed as a violation of community guidelines.
  • bailey78
  • mitekillem
    • 0
      mitekillem  

    • Mars has water, it's just at the poles and under the ground.
      Are they suggesting that the solar wind pushed it to the poles?
      Or evaporated it everywhere, except for the poles, which have weak-spots and take in more solar radiation than other areas of the planet. i.e. like at the poles here on Earth, we see this radiation as the Aurora Borealis.

      I've learned not to question the importance of magneticism, as it holds the stars in place, keeps planets on course, affects the tides in the sea, affects the spin of water down a drain, and even holds the molecules in our bodies together, and keeps them from flying apart.

    • 1 year ago
  • pukemnukem
    • 0
      pukemnukem  
    • mitekillem:

      You got a few conceptual errors there....

      Stars are not held in place by anything. Stars are constantly moving. Depending on the location of where the observation is made, things are either stationary or moving...but that doesn't necessarily imply their actual state.

      The stars themselves are held together due to gravitational force...nothing else. This is why stars will eventually collapse into themselves if they can no longer produce sufficient energy for fusion or they explode if their fusion energy can overcome gravitational forces. Magnetism does not play a major role at all.

      As per chemical bonds...again, this depends on the actual situation. Metallic bonds, which are due to the valance electrons moving freely in an electron sea within the material are very influenced by magnetism. We can see this as metals are usually very good at conducting electricity and temperature. This also explains why you cannot see through them.

      However, other bonds, such as covalent bonds, which can be extremely strong due to their directional nature (such as diamond) are due to elements sharing valance electrons through bonding. This is not to imply that applying a charge to a substance would increase bonding nor do magnetism influence their formation.

      Ionic bonds are due to elements completely losing or gaining valance electrons, such as table salt. Again, there is a charge to each ion, and they attract each other, but placing the elements in a field will not influence them. So say if you just spilled a bunch of salt on your kitchen table, you couldn't just pick them up with a magnet like you could with pieces of iron. Similarly, you could not extract salt from water just using a powerful enough magnetic field. (interesting side note, both water and dry salt are bad conductors. The reason you don't want to take a radio in the shower with you however is the impurities in the water will make it much more conductive hence...shocky, shocky. I find this interesting as it is very counter-intuitive to me).

      Then you could go even farther into weaker bonds, such as Van der Waals bonds which heavily influence things like plastics and how they form chains, increasing physical characteristics beyond what would be normally expected.

      Ah...but I am a dork and an engineering student...so I am always having to write annoying lab reports about this crap. Please don't think of me as an expert or that I know exactly what I am talking about. If I have learned in four years of schooling...I have a shitload left to learn.

    • 1 year ago
  • Schnookums
  • PressCore
    • +1
      PressCore  
    • Schnookums:

      In 2000 there was a TV series staring Jessica Alba called Dark Angel. The
      premis of the show was about an EMP from a CME knocking out the grid,
      frying all the transformers, and all the computers on earth. They discussed
      that on one History channel documentary saying it would take 8 years for
      the Northern Hemisphere to recover from it if it hit here. And even then it
      would take the combined resources of all the Southern Hemisophere's
      industrialized nations to manufacture emergency transformers and ship
      them here by sea before the USA could recover. By then the USA would
      realy be in the poorhouse. BTW, though I didn't comment on your article
      about BIS in Switzerland, I did blog it and the source at the link. Great
      story you contributed. I've lived in Geneva for 3 months in 1979, seen
      Gold in bank windows, spent shiny Silver half franks , and known of the
      supreme confidence the Swiss have in their 100 frank notes. I see why.

    • 1 year ago
  • Steamed_N_More
  • Jeremy_Benson
  • Steamed_N_More
    • 0
      Steamed_N_More  
    • Jeremy_Benson:

      The ability for our planet to retain water is assisted by the magnetospheres protective properties from solar winds, within certain energy levels. The shield isn't the only factor involved. It never has been what is or isn't needed, it's what works and how.

    • 1 year ago
  • Jeremy_Benson
    • 0
      Jeremy_Benson  
    • Steamed_N_More:

      Is or isn't needed, works or doesn't work, it sounds the same to me in this case. How is another story entirely. I'm reading this in the context of 'what do we look for when we look for planets that have or could have life supporting properties, including water and atmosphere.'

    • 1 year ago
  • ejasun
    • +2
      ejasun  

    • Earth's Magnetic Field Is Fading...
      Earth's geodynamo creates a magnetic field that shields most of the habited parts of our planet from charged particles that come mostly from the sun. The field deflects the speeding particles toward Earth's Poles.

      Without our planet's magnetic field, Earth would be subjected to more cosmic radiation. The increase could knock out power grids, scramble the communications systems on spacecraft, temporarily widen atmospheric ozone holes, and generate more aurora activity.

      A number of Earth's creatures, including some birds, turtles, and bees, rely on Earth's magnetic field to navigate. The field is in constant flux, scientists say. But even without it, life on Earth will continue, researchers say.

      "There are small fluctuations, which lead to nothing, and large ones, which we know from the geologic record are associated with reversals," said Peter Olson, a geophysicist at Johns Hopkins University in Baltimore, Maryland.

      http://news.nationalgeographic.com/news/2004/09/0909_040909_earthmagfield.html

    • 1 year ago
  • Ian_Judge_Lord
    • +4
      Ian_Judge_Lord  

    • Bloxham, Jeremy, & Gubbins, David. (1989, December). The Evolution of Earth’s magnetic field. Scientific American, 68-75.

      Cussler, Clive. (1999, December 6). Atlantis Found. (534p.) Florida: G.P. Putnam’s Sons.

      Cussler, Clive & Kemprecos, Paul (2005, July 26). Polar Shift. (433p.) New York: G.P. Putnam’s Sons.

      Dudeney, John, & Rodger, Alan. (1993, February 4). Merging at the magneto-pause. Nature, 36, 407.

      Fuller, Mike. (1989, June 22). Fast changes in geomagnetism. Nature, 339, 582-3.

      Fuller, M., Herrero-Bervera, E., Laj, C., Mazaud, A., & Weeks, R. (1991). Geomagnetic reversal paths. Nature, 351, 447.

      Harrison, C.G.A., & Somayajulu, B.L.K. (1966). Behaviour of the Earth’s magnetic field during a reversal. Nature, 212, 1193-1195.

      Hoffman, K.A. (1991). Long-lived transitional states of the geomagnetic field and the two dynamo families. Nature, 354, 273-277

      Hoffman, K.A. (1992). Dipolar reversal states of the geomagnetic field and core-mantle dynamics. Nature, 359, 789-794.

      Hoffman, Kenneth. (1988, May). Ancient magnetic reversals: Clues to the geodynamo. Scientific American, 76-83.

      Jackson, Andy. (1992, July 16). Still poles apart on reversals. Nature, 358, 194-5.

      Jacobs, J.A. (1984, May 10). Earth science: What triggers reversals of the Earth’s magnetic field? Nature, 309, 115.

      Jacobs, J.A. (1995) The Earth’s Magnetic field. Contemporary Physics, 36, 4, 267-277.

      Langel, R. (Ed. Jacobs, J.A.). (1987). Geomagnetism (Academic, San Diego). 1, 249-512.

      Larochelle, A.; & Morley, L. W. (1964). Paleomagnetism as a means of dating geological events. Geochronology in Canada. Royal Society of Canada Publication, 8, 39-50.

      Lewin, Roger R. (1992, January 25). Earth’s Field flips flipping fast. Science, 26.

      Matthews, P.C., & St. Pierre, M.G. (Eds. Proctor, M.R.E., Matthews, P.C., & Rucklidge, A.M.). (1993). Solar and planetary dynamos. 211-218. Cambridge University Press.

      McElhinny, M.W., & Merrill, R.Y. The Earth’s magnetic field (Academic, London), 183.

      Monastersky, Richard. (1991). Earth Burps and magnetic flips. Science News, 141, 14.

      Monastersky, Richard. (1993, June 12). The Flap over magnetic flips. Science News, 143,
      378-380.

      Roach, John. (2004, September 27). Why does Earth’s Magnetic field flip? National
      Geographic News.

      Tsygankov, S.S. (2006). On The Possible mechanism of geomagnetic field inversion.
      Doklady Physics, 51, 7, 393-396.

    • 1 year ago
  • coolplanet
    • +2
      coolplanet  

    • It's because earth has trees and grass and plankton and algae to transpire and recirculate a constant body of water as an atmosphere.

    • 1 year ago
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