The previous picture was of a Valentine-shaped cloud taken by WISE. However, that's only one part of a vastly larger complex of gas and dust called IC 1805. Right next to the Valentine (well, in cosmic terms, it's actually a couple of hundred light years away) is another star-forming region, another giant cavity carved by the winds from mighty stars.

But, in a fit of galactic irony, this particular cavity is shaped more like an actual human heart! You can even get a hint of the chambers inside it. Together, these two objects are colloquially called the Heart and Soul nebulae... and this one is the heart.

Higher res version.
Original release.

Image credit: NASA/JPL-Caltech/UCLA