Happy Valentine's Day from Spitzer Space Telescope! This image is of a region called W5, part of a bigger complex of gas and dust shining 6000 light years away in the constellation of Cassiopeia. The resemblance to a Valentine is remarkable!

What you're actually seeing here is an enormous star-forming factory 150 light years across. Deep in its (haha) heart massive, hot, and bright stars are being born. When they switch on for the first time, they blast out a flood of ultraviolet light as well as a fierce wind of subatomic particles. These eat away at the cloud from the inside-out, forming an enormous cavity. It's the edges of this cavity that form the cosmic valentine.

[Note: a slightly different view of this cloud is later in the gallery. Also, my apologies to Debbie Harry for the title of this image.]

My blog post about W5.
Original release.

Credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA