Hercules Cluster      M13

M13  is the brightest globular cluster in the Northern Hemisphere and has approximately 300,000 stars where in these relatively crowded quarters the average separation is around one light year apart. It lies 23,000 ly from the Earth in Hercules. Imaged at Kitt Peak with Steve White and Al Medina with a 16" LX200 scope. The big radio telescope at  Arecibo Observatory  sent a message to this cluster in 1974. Click on  Message to M13