Our Galaxy jealously guards its secrets. And if it lets you discover any, it’s very slowly.
We live on a huge island of glowing matter surrounded by darkness, which only a hundred years ago was the entire universe for us. That it is only one of many similar objects separated by millions of light years of vacuum, we learned only in 1923. This groundbreaking discovery, second only to the Copernican Revolution, was made by Edwin Hubble, who worked at the Mount Wilson Observatory near Los Angeles.
In the part of the universe under modern research there are several hundred billion similar islands, called galaxies in astronomy. The one we live in is referred to as “our Galaxy” or simply “the Galaxy”, traditionally written with a capital letter. There is also the confusing term “Milky Way,” the proper meaning of which must be read in the context of a sentence.
This term comes from the myth about Herakles, the offspring of Zeus and the mortal earthling Alcumene. According to one of its versions, the ruler of Olympus decided to gain immortality for his son, and in order to achieve this, he put him to the breast of his sleep-stricken wife Hera. Herakles suckled so violently that the goddess awoke and pulled his breast out of his mouth. The milk (γάλα) gushed out into the sky and spilled into a stream called in ancient Greece the Milky Circle (Γαλαξίας Κύκλος). The Romans assimilated this name under the form Via Lactea (Milky Way), which became established in most European languages.
A Mistake Under the Cloud
From the outside, our Galaxy looks like a thin disk with a diameter of 100,000 and a thickness of just 1,000 light-years. We are looking at it from the inside, so when we look along the disk’s radius, we see many more stars than if we were looking along its axis. There are so many that the eye literally gets bogged down in the stellar myriad that merges into the pale silver belt of the Milky Way proper.
In ancient times it was visible from every place on Earth. Today — it is drowning in the increasingly bright lights of our civilization and hiding behind the increasingly dense…