Object Analysis

Messier 13 (M13), often called the Great Globular Cluster in Hercules, is a globular cluster of several hundred thousand stars in the constellation of Hercules. It is one of the brightest and best-known globular clusters in the northern celestial hemisphere. Discovered by Edmond Halley in 1714, it is located about 22,180 light-years from Earth.

The cluster is about 145 light-years in diameter and is packed with stars, the density of which increases toward the center. In the core of M13, stars are about 500 times more concentrated than in our solar neighborhood. If observing the sky from a planet in the core of M13, the night sky would be blazing with thousands of stars brighter than Venus/Jupiter appear to us.

M13 was the target of the famous Arecibo message of 1974, which transmitted a radio signal carrying basic information about humanity and Earth towards the cluster. However, the cluster will no longer be in its current location when the message arrives in roughly 25,000 years, making contact unlikely.