By Paul Levesque Popular Astronomy Club
Summer is a good time to see our home galaxy.
It’s June, so we’re in the middle of the Milky Way season. No, this is not the best time to enjoy the popular nougat-filled candy bar (which is year-round) but rather the time when we get the best views of our home galaxy.
From April to September, the Milky Way is almost over your head and appears as a hazy stream of light up to 30 degrees wide that radiates from south to southwest. When we see what we call the Milky Way, what we actually see is part of the galaxy that our earth calls home, also known as the Milky Way.
Every single star we see in the night sky is in the Milky Way galaxy. The stream of light that we call the Milky Way, and which Chinese astronomers called the “Silver River”, consists of stars that are too far away to be solved individually with the naked eye and that are within one of the galaxy’s spiral arms.
From our perspective, the center of the Milky Way galaxy can be found in Sagittarius, one of the constellations in the zodiac. Just last month, astronomers took the first image of “Sagittarius A”, a massive black hole in the middle of the Milky Way that the galaxy orbits.
People also read …
The name “Milky Way” for the stream of light in the sky goes back to ancient Greece. Greek legend has it that the Milky Way came from milk spewed from the breast of Hera, the goddess of women and marriage who was the wife of Zeus and one of his many lovers.
The term “Milky Way galaxy” is actually a bit redundant. This is because the word “galaxy” has its roots in “gala”, the Greek word for milk.
Until about 100 years ago, there was no need to use the word “galaxy” in pluralization, because astronomers believed that the Milky Way was the only galaxy and that it constituted the observable universe. This is understandable when you consider that it takes about 100,000 years for a ray of light to travel across the Milky Way, and that our home galaxy contains billions of stars and countless other celestial objects.
As vast as the Milky Way was, astronomer Edwin Hubble believed that it was not the only galaxy and that many of the objects then classified as “nebulae” and thought to be gas clouds were in fact separate galaxies outside the Milky Way. In the 1920s, Hubble definitely proved its theory, and his other astronomers soon found and mapped many other galaxies.
Today, it is estimated that there are at least 100 billion galaxies in the universe and probably many more. This means that there are at least a dozen galaxies for every person now living on earth.
We now know that the Milky Way is a barred spiral galaxy, a fairly common type of a fairly average size. But we have also found that each galaxy we study has unique characteristics that set it apart, just as we are all individuals.
The rustic origin of the Milky Way’s name goes back to a time when most people lived on farms or in villages in the countryside and therefore could easily see the stream of light in the sky when they looked up on clear, moonless nights in spring and summer. At that time, even city dwellers could raise their heads and watch the Milk War as they crossed dark streets.
Then came progress, which brought with it artificial lighting and a massive population shift from the country to urban and suburban areas. As a result, it is estimated that almost 80% of Americans, including those of us who live in the Quad-Cities metro area, now live in places where it is virtually impossible to see the Milky Way due to ambient light – a figure that is sure to increase as we continue to grow in numbers and spread further out.
So if you want to see the Milky Way, you have to travel to a place far away from the city lights. Choose a night when the sky is clear and a time when the moon is below the horizon, because the glare from a full moon can wash out the Milky Way as safely as a street lamp can.
Looking up at the Milky Way makes me wonder if there are any alien astronomers observing from one of the many other galaxies and seeing our galaxy from a point of view that we can not share. If so, they may be wondering who can look back on them.
PAC invites the public to its next observation session at the Niabi Zoo on June 18 at sunset and on the third Saturday of each month through November. For more information, visit the PAC website at https://www.popularastronomyclub.org/ or search for the club on Facebook.
#QuadCities #Popular #Astronomy #Club #Milky #season