Comet 21P/Giacobini-Zinner

Description:

Comet Giacobini-Zinner was discovered in December 1900. It has a nucleus about 2 km in diameter and takes 6.6 years to complete its orbit around the Sun. Each time it passes near the Sun, it leaves some debris of ice and rock. Earth passes through some of these debris clouds in early October each year giving rise to the meteor shower known as Draconids (sometimes referred to as Giacobinids)

In this photo, the comet passed very close to the open cluster Messier 37 and, fortunately, the sky was clear enough to allow me to immortalize it in a photo.