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    That Square Hole In The Sun
    By News Staff | May 12th 2014 07:44 PM | 3 comments | Print | E-mail | Track Comments
    Last year, people began wondering why part of the sun was missing.  What had happened was that changes to the magnetic field were allowing hot plasma to fly off into space toward Earth, creating a coronal hole.

    Coronal holes are actually happening less right now, because we are experiencing a solar maximum. During this portion of the recurring cycle, the number of coronal holes decreases. During solar max, the magnetic fields on the sun reverse and new coronal holes appear near the poles with the opposite magnetic alignment.

    The coronal holes then increase in size and number, extending further from the poles as the sun moves toward solar minimum again. At such times, coronal holes have appeared that are even larger than this one. They are the source of a high-speed wind of solar particles that streams off the sun some three times faster than the slower wind elsewhere.


    Credit: Solar Dynamics Observatory/NASA.

    A coronal hole, almost square in its shape, is one of the most noticeable features on the Sun in a new picture seen last week. 

    A coronal hole is an area where high-speed solar wind streams into space. It appears dark - in extreme ultraviolet light - as there is less material to emit in these wavelengths.

    Inside the coronal hole you can see bright loops where the hot plasma outlines little pieces of the solar magnetic field sticking above the surface. Because it is positioned so far south on the Sun, there is less chance that the solar wind stream will impact us here on Earth.


    Credit: Solar Dynamics Observatory/NASA.

    Comments

    Is this title linkbait for conspiracy nuts? Who cares about the large scale shape of an arbitrary coronal hole? If you're going to mention the shape at all at least write-up an explanation of why it is silly to ascribe any significance to it.

    Hank
    The conspiracy nut link bait verbiage is, in this instance, created by NASA. There is no explanation for its shape, it just happened when they were taking a picture, so they sent out a press release about it. Their PR effort seems to have worked - I googled "NASA square hole sun" just now and it has almost 5 million hits, and we are nowhere near the front page.
    Alright, It's not your fault.

    But NASA PR intern who probably won't read this page: I'm very disappointed in you trying to exploit the crackpot crowd for publicity.