Where is it?

In the constellation of Serpens Caput (the Snake’s Head). It lies on the outskirts of our Galaxy about 24,500 light years from Earth.

How big is it?

It is home to more than 100,000 stars, with some estimates saying it has as many as half a million. It is about 165 light years across.

How old is it?

Not much younger than the Universe, it is thought to be about 13 billion years old, more than twice as old as our solar system. However astronomers have observed some much younger stars, perhaps created from collisions between stars or the transfer of mass from binary stars.

Why is it called M5? 

In the late 1700s French astronomer Charles Messier started listing strange objects that didn’t seem like ordinary stars. On May 23rd 1764 he found it and labeled it as M5, because it was the fifth on his list. 

Finding M5

If it is very clear and you have very good eyesight, you might just see it. Otherwise you will need binoculars or a telescope. Only a big telescope will show it as being made up of many stars.

From the northern hemisphere looking south it is highest at about 10 pm in mid-June. Because the stars return to the same place in the sky some two hours earlier with each passing month, it’s highest in the sky around 8 pm by mid-July. 

Serpens Caput is a relatively faint constellation to the left (as you look south) of the much brighter stars Arcturus and Spica. Using a fist at arm’s length for a guide, M5 is a good two fist-widths to the southeast of yellow-orange Arcturus and three fist-widths to the east of blue-white Spica, the brightest star in the constellation of Virgo.