The Sun is squirting into interplanetary space


I saw this image in the paper the other day and resolved to find out more about it. NASA gives it the following caption:

Still from video of Jan 19, 2012 long duration solar flare and coronal mass ejection (CME) which is expect to reach Earth on Jan 21, 2012.

So (having established that 21 Jan has been and gone and was clearly nothing to worry about) what the heck is a solar flare?

A solar flare is an intense burst of radiation which is caused by plasma (electrically charged gas) slamming into the surface of the Sun. Basically a massive explosive event.

And what the heck is a coronal mass ejection?

A coronal mass ejection is when, instead of colliding violently with the surface of the Sun as with the solar flare, the plasma is directed outward and – as NASA explains – is “squirted out into interplanetary space”.

Both types of explosion release a LOT of radiation of all wavelengths which apparently affects the Earth’s local space weather.

I couldn’t find out much about the imaging equipment that records pictures like the one above but I would assume it records ultraviolet wavelengths and converts them into colour images. Ultraviolet radiation monitoring seems to be the most common way of measuring coronal activity and plasma caught in the magnetic loops of the corona gives off ultraviolet light so that would make sense.

Don’t you think it’s a little odd that the conversion from UV to the visible spectrum has been set as blue and green, though?  It makes the sun look like a strange version of earth with a particularly vicious aurora!