M33, along with our own Milky Way and the Andromeda Galaxy (M31), is a member of the Local Group of galaxies. M33 is not as large as either the Milky Way or Andromeda and is considered an "average" sized spiral galaxy. It is approximately half the diameter of the Milky Way with an estimated mass of about 40 billion solar masses. At a distance of 3 million light years, its location is a little farther from our position than the Andromeda Galaxy. It is approaching our location in the Milky Way at a speed of 182 km/sec. Correcting for the Sun's motion around our galactic center, M33 is approaching the Milky Way at 24 km/sec. Many areas of nebulosity can be seen in the arms of M33. These stand out with the red glow of ionized hydrogen gas. The largest of these is designated NGC 604 and is located in the upper left of the image above. These areas in M33 are similar in nature to nebulae such as M42 (The Great Nebula in Orion) and are the birth place of new stars.