This is CBS Eye on the World with John Bachelor. Here's John Bachelor.

This is CBS Eye on the World. I'm John Bachelor. I welcome Dr. Ken Croswell, author of the

Alchemy of the Heavens, searching for meaning in the Milky Way, to take us to the Milky

Way. A galactic enterprise can as long admired as beautiful, and he now writes in the proceedings

of the National Academy of Sciences. A revelation about the Milky Way, about our place in it,

our solar system, can a very good evening to you. And the Milky Way is a spiral galaxy,

but to do some history, the revelations of spiral galaxy you date to the mid-19th century,

the Whirlpool Galaxy. And that was sometime before we could perceive our own galaxy because

we're inside that spill of stars across the sky. What did the Whirlpool Galaxy teach us?

What does it mean to be a spiral galaxy? Good evening to you.

Good evening, John. The Whirlpool Galaxy is a stunning spiral galaxy. It's still one

of the most beautiful galaxies we know. And there's a picture of a great picture from Hubble

that appears in my article in the proceedings of the National Academy of Sciences. We discovered

a spiral structure in 1845, where I should say Lord Ross in Ireland was the first to make

out the spiral structure of that galaxy. And soon after we discovered a number of other

spiral nebulaes, that's what they were called back then. We now know that those are other

galaxies that resemble our own, located well beyond the Milky Way. And almost from the

stars, a lot of astronomers speculated that the Milky Way might be a spiral galaxy, but

it was only a century later that they were able to prove that in the early 1950s, as I tell

the story in my book, The Alchemy of the Heavens, William Morgan at Yorkies Observatory

in Wisconsin, and his colleagues plotted the positions of young stars and the gas clouds

that give birth to those stars. And he was able to make out the three nearest spiral

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