M33 is the only other spiral galaxy known in the Local Group. At 3 million light-years, M33 is the second closest spiral galaxy. M33 is thought by some to be a satellite galaxy to massive M31 . M33 is close enough to appear twice the angular size of the full moon , when viewed with binoculars. Globular clusters in M33's halo appear unusual and might be much younger than globular clusters in our Galaxy's halo .
Specific rights apply .