This is ARP 148 (aka Mayall's Object), it's found 500 million light-years away in the constellation of Ursa Major. What you can see is the aftermath of a collision between two galaxies.
The blue ring on the right was created when the white tail on the left passed through the original galaxy. Think of it like dropping a pebble in some water-- gravity draws the water inwards, which then clashes and ripples outwards again. This is the same principal, only on a ridiculously massive scale! When the white tail passed through the galaxy on the right, the gravity drew matter inwards, thus causing it to clash and ripple outward in a propagating density wave.
Normally in these galactic rings, you'll see spikes of star formation due to the aggravated matter clashing together. I always say it, and I'll say it again, take a look guys... this is the future for the Milky Way!
Also, It almost like a portal! Stargate anyone?