This is one of the few times I've broken my "let the subject speak for itself" rule. The image you are looking at is actually baking soda and vinegar reacting on a black plate. The "comet trail" is the baking soda and vinegar reaction, and the "planets" and "comet" are reflections of the microscope's LED lights in the glass and liquid. Even though this image occurred completely by accident, the finished image was too well liked to scrap.
The image is 5x7, double matted and framed to 8x10. The inner mat is black, the outer mat is white, and the frame is black.