Starting in Our Own Galaxy
It’s been a tumultuous November and I’m glad that December is finally here. I spent much of last month on travel, hence my light posting schedule. But, now I’m back and catching up on something I LOVE to do: read about astronomy.
Top of my pile was an amazing article in the December 2010 National Geographic by Ken Croswell called “Star Struck.” It’s illustrated by well-known astrophotographer Wally Pacholka and also includes views of our galaxy from the great observatories.
No matter how many times I look at astro-images, the cosmos still takes my breath away. And, that’s kind of what it does for Ken, too. His article explores the Milky Way in lovely, poetic detail. Not for Ken (or me) the pedantic descriptions of our home galaxy. To my delight, he uses language that draws a great picture in your mind of this behemoth galaxy we call home:
“It’s hard to be modest when you live in the Milky Way.
Our galaxy is far larger, brighter, and more massive than most other galaxies. From end to end, the Milky Way’s starry disk, observable with the naked eye and through optical telescopes, spans 120,000 light-years. Encircling it is another disk, composed mostly of hydrogen gas, detectable by radio telescopes. And engulfing all that our telescopes can see is an enormous halo of dark matter that they can’t. While it emits no light, this dark matter far outweighs the Milky Way’s hundreds of billions of stars, giving the galaxy a total mass one to two trillion times that of the sun. Indeed, our galaxy is so huge that dozens of lesser galaxies scamper about it, like moons orbiting a giant planet.”
The article goes on to talk about the details of the Milky Way, derived from astronomy’s most recent explorations of it. Modern research is telling us a lot about the galaxy, and in particular, the action of its central, supermassive black hole in tossing stars out of our galaxy via its gravitational influence on binary pairs. like You don’t have to be a scientist immersed in the detailed study of the Milky Way and its place in the hierarchy of cosmic structure to appreciate knowledge like this. It’s fascinating stuff. And, made even more so by writing like Ken’s and images like Wally’s. Go check out the article and immerse yourself in the Milky Way!