APOD 4.3

I actually read about this late last night. While in the visible spectrum, you can clearly see the two spirals, in other spectrums there are other, what are called "phantom" spirals. Here is another picture:

The phantom limbs, which are visible in the infared and X-Ray parts of the spectrum are, after 50 years, believed to be caused by a shockwave that violently heats up gas in that area. These arms have been a mystery for a long time, and astronomers are happy to finally know what's up.