Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2015 December 19 Star Streams and the Whale Galaxy Image Credit & Copyright: R Jay Gabany (Blackbird Observatory) Collaboration: David Martínez-Delgado (University of Heidelberg), et al. Explanation: NGC 4631 is a spiral galaxy found only 25 million light-years away, toward the well-trained northern constellation Canes Venatici. Seen ege-on, the galaxy is similar in size to the Milky Way. SpaceWeather.com.