PHOTO COURTESY ESA
M33 is a classical spiral galaxy in the constellation of Triangulum. It lies approximately 2.6 million ly from Earth and has an overall magnitude of 7. It is best seen with low magnification and a wide field of view under dark skies, as its low brightness does not stand up well to high power. M33 is around 52,000 ly across making it around half the size of our own galaxy. In the night sky it has a diameter about the same as the full moon.