In 2010, Comet 103P/Hartley, otherwise known as Comet Hartley 2, visited the inner solar system and put in a favorable appearance, becoming barely visible to the unaided eye.  In this view, we see it giving off the characteristic green color that many dim comets exhibit, in the constellation Perseus, between the upper tip of the outline and and Double Cluster at the top of the image.  Unannotated image.