The Rotten Fish Nebula

At first glance, it is almost an absence: a dark stream that seems to wipe out the stars, like a tear in the starfield. This blackness is in fact a dark nebula: a cloud of dust and gas so dense that it hides everything behind it. Astrophotographers found in it a vague fish shape and nicknamed it the Rotten Fish.

But this cloud is anything but dead: inside, stars are being born. As they form, they spit out powerful jets of matter that slam into the surrounding gas and light it up in small reddish patches. Astronomers call these glows Herbig-Haro objects, after the two researchers who described them.

The whole scene lies about 1,000 light-years away, in the constellation of Cepheus, within a vast complex of dark clouds, the Cepheus Flare, suspended above the plane of our galaxy. It is so faint that it took more than 25 hours of exposure to reveal it. It even reveals, shining through, a distant spiral galaxy lost far behind the cloud.