The sky’s the limit!
Well, up to now, the Milky Way galaxy has been the limit. Humans have never gone into space beyond our Milky Way galaxy. This is not surprising, as to breach the diameter of our barred spiral galaxy would take a space explorer 100,000 light years in travel time.
There isn’t a compelling reason to leave the galaxy that is home to our solar system anyway. In order to cross the great distance to get beyond the Milky Way, you would potentially have to pass by some of the 400 billion other stars that encompass it or travel 1,000 light years to bust vertically out of our frisbee-shaped galaxy. Nor would you want to travel to its center. At the heart of the matter, so to speak, is a giant black hole.
You get the picture; the Milky Way is big. Heavy, too, with a mass of 750 billion to 1 trillion solar masses, or 750 billion to 1 trillion times the mass of our sun!
What we are seeing when we say that we see the Milky Way is just a hazy band of the bright stars observable in the galaxy’s horizontal plane. The Milky Way seems to divide our sky into two hemispheres. We see the bright arching band of stars from our location on the arm of the spiral Orion, 26,000 light years from the center of the galaxy. Yet, in the darkness that defines the Vineyard, this dense and luminous band is impressive, even if we can only see .000003 per cent of the whole Milky Way galaxy.
If you were to ask the ancient Greeks how the Milky Way came to be fixed in our sky in the heart of the constellation Sagittarius, they would tell you that it came from milk that was spilt when Hera suckled Heracles. The word “galaxy,” in fact, is derived from “galakt,” meaning milk.
Eastern Europeans called the Milky Way “the Roman Road.” Following it would provide pilgrims the direction to get to Rome. In Sanskrit, the Milky Way is the “Ganges of the Heavens,” as important to the sky as the great river is to the earth.
Though Greek philosopher Democritus first observed and noted the Milky Way, it was around long before his observations. The Milky Way is ancient, definitely older than dirt, at a ripe old age of 13.6 billion years. This makes our Milky Way galaxy only slightly younger than the universe itself, which goes back approximately 13.7 million years.
This wise old galaxy knows it won’t be around forever. It is unfortunately on a collision course with the Andromeda galaxy and impact between the two galaxies is estimated to occur in about three billion years. Only time will tell what the results of the collision between these two super systems will be.
In the meantime, enjoy the sight of the galactic profusion of stars above our heads and around our planet. While this Milky Way in the sky may not satisfy your sweet tooth with chocolate, nougat and caramel, it will sweeten your nights with its stellar display of stupendous stars.
Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.