M92 is an example of a globular star cluster. This cluster is a collection of tens of thousands of stars clumped together forming a globe of pinpoints of light.
There are dozens of these clusters that can be viewed in the summer sky with a small telescope. There are very few that you can see in the winter sky.
The astronomer Harlo Shapley carefully plotted the direction and distance of these clusters, finding they made a sphere in the direction of the part of the Milky Way visible in the summer months – showing him the location of the center of the Milky Way Galaxy. Shapley was able to determine that our solar system is about 30,000 light years from the center of the Milky Way, two-thirds of the way from the center to the outer edge.