Located at 7,000 light years, M4 may be the closest globular cluster to our own sun. Shining at magnitude 5.6, it can be seen with the unaided eye under good conditions. At 26 arc minutes, M4 is nearly as large as the full moon, with a real diameter of about 55 light years. Located in Scorpius, It is one of the most open and loose globular clusters, and would be astonishing if not obscured by thick clouds of obscuring interstellar dark matter in the region of Antares and Rho Ophiuchus.