HUGE Coronal Hole On The Sun

January 4, 2015, by Ken Jorgustin

huge-coronal-hole
Source: Atmospheric Imaging Assembly, aia.lmsal.com

There is suddenly a HUGE hole in the Sun’s atmosphere as shown in the image displayed above from the ‘Atmospheric Imaging Assembly’ (AIA) for the ‘Solar Dynamics Observatory’ (SDO). A larger image can be seen below of this apparently unusual event (given it’s size).


 
Coronal holes occur regularly on the Sun’s surface, although usually much smaller than this.

 
What is a coronal hole?

A coronal hole is an area on the Sun where the magnetic field ‘opens up’ and lets the Sun’s solar wind escape into space. It can only be ‘seen’ by looking at the extreme ultraviolet frequency spectrum of the Sun, as imaged by a particular NASA satellite in space called “SDO” which is the source for most of the Sun’s imaging that you see today on the internet.

 
What is solar wind?

The solar wind is a stream of plasma released from the Sun. It consists of mostly electrons and protons with varying energies. The solar wind flows outward at supersonic speeds to great distances. The solar wind can create the phenomena of the aurora (northern and southern lights), and if strong enough, geomagnetic storms that can change the direction of Earth’s magnetic field lines and create strong currents in power grids.

 
Why is this particular Coronal Hole worthy of a post?

It reminds me of the awesome power of the sun, and it’s sometimes unpredictable and powerful behavior. It also reminds me of the risks and dangers we face because of it. Things like power grid failure. While a moderate solar event can temporarily affect our modern technology, an extreme solar event could temporarily or permanently affect our way of life. This is why, when I sometimes become aware of a seemingly unusual solar event, I raise an eyebrow…

The solar wind spewing from this particular monstrous coronal hole is mostly flowing south of our planet right now (fortunately). However we will be intercepting some of it and NOAA expects polar geomagnetic storms within 24 to 48 hours.

 
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A closer view of the coronal hole with earth in proportion.

 
109-earth-diameters-across-the-sun
To give you an illustration of the magnitude of the Sun, I’ve superimposed 109 Earth’s across the diameter of the sun. That’s how big it is!

 
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This extreme ultraviolet image illustration from SDO shows the curved lines tracing the Sun’s magnetic field during the time of this particular coronal hole.