No one knows what that blue thing in the picture is. It's called "Hanny's Voorwerp" (Hanny is the name of the Dutch guy who discovered it; Voorwerp means "object" in Dutch). It's gas of some kind, and something is (or was) lighting it up, but no one can figure out what is (or was) doing the actual lighting up.
It looks like a little blue alien guy to me, his arms hugging something we can't see. Or maybe he's doing the hokey-pokey. You put your voorwerp in, you put your voorwerp out....
The theory currently making the rounds is that the galaxy in the middle of the picture once had a big, bright quasar that lit up the voorwerp (I love that word), then disappeared. So the quasar is gone, but evidence of it's light remains in the voorwerp.
The coolest thing about it is that is was discovered by an amateur astronomer. There's this site called Galaxy Zoo where regular folks can log into a vast catalog of galaxy images and classify them, thus helping out the scientific community, not to mention being able to look a a bunch of cool galaxy pictures. SETI (Search for Extra Terrestrial Life) does this too. Hanny was doing just that, classifying galaxies, saw the blue blob, told the Galaxy Zoo about it, and the rest is history.
Don't know if they're gonna let Hanny name it or not.
