The image title is a little incomplete. As well as the Heart Nebula and the Soul Nebula, this image also includes the Fish Head Nebula as well as a number of star clusters within each.

The dominance of red colour in the image is a result of the high ratio of hydrogen relative to other gases in the objects, as well my lack of knowledge in how to process one shot colour images to boost the signals from the other gases (mostly oxygen).

More information about these objects can be found on the Wikipedia pages for the Heart Nebula and the Soul Nebula.

This image is the other one of the two that were captured the first time I attempted to set up both of my telescopes for simultaneous shooting.

You can view this image in the WorldWideTelescope by clicking here.