Wednesday, 15 June 2011

Coronal Mass Ejection (CME)

I was doing my usual browsing around the internet, looking for interesting news, and I came across this. This is a time lapse taken by the SOHO satellite, which sits at a very unique point in space where Earth and the Sun's gravity "cancel out" (This is called a Lagrangian point, and there are in fact 5 of them). This results in the satellite always lying between the Earth and the sun, which makes it an ideal spot to watch the sun from. In these images, they block out the sun (as it would saturate the image), so that we can see the active corona (hence the image is called a coronagraph).

Here we can see something called a coronal mass ejection (CME). The Sun's surface is a rather turbulent place, since it is not solid like the Earth's. This results in magnetic fields getting twisted together to form "closed loops", kind of like a net, which traps plasma. Eventually when the plasma pressure exceeds the magnetic pressure, the net bursts, spewing out billions of tons of very energetic radiation (+-800km/s). This particular one, luckily, was not pointed towards the Earth.

Things are like this are going to become more and more frequent as we head into the period known as solar max (the sun is most active during this) which will peak next year.

Oh, and in case you were wondering, that horizontal bright line to the left of the sun, is mercury. It appears so bright to the camera that light bleeds into adjacent pixels.
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4 comments:

  1. Unknown15 June 2011 at 14:46

    Ah, also, just to cover my ass. Technically, the magnetic loops are not closed (since this is impossible), the magnetic field lines are just so curved and dense that they form a neck, which are close to closed.

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  2. Unknown15 June 2011 at 14:48

    Also, credit to www.spaceweather.com, and the SOHO team.

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  3. SnowPony21 June 2011 at 08:50

    So what would happen if those bursts were in the path of Earth?

    And how is Mercury affected being so close to the sun?

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  4. Unknown21 June 2011 at 13:54

    The END of the WORLD... as you know it, maybe. When these energetic particles collide with our magnetic field, all kinds of disruptions are experienced. Power grids become overloaded, causing power outages. Radio communications are disrupted. Satellites can be damaged, or ouright destroyed. Passengers on commercial aircraft will be subjected to a lot of radiation.

    In 2003 the Earth experienced a glancing blow from a huge CME, and several of Escoms power transformers blew. A few hundred years ago there was a direct hit from a major storm, causing every single telegraph wire to melt from overload (Fortunately man was not as dependent on technology back then.

    A direct hit from a major CME will make life very tough on Earth. Think where we would be with no electricity. But physically we will be fine (unless you happen to be at high altitudes, or actually in space).

    Mercury is basically cooked. It has no atmosphere, te temperatures are extreme, all because it is right next to the sun.

    Its not all doom and gloom though. We have satellites like SOHO which can give us at least an hours warning, which is enough to get satellite operators to shield them, and for power grid operators (like escom) to reduce loads in the power grid.

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