You know what time it is. It's time for Ask a Space Man. I'm Paul Sutter. You've got questions and I've

got answers. You know how this show works, but just in case, just in case, just one more

time I'm going to explain how. You go online to askas spaceman.com or you go email at ask a spaceman

at gmail.com or you use the hashtag Ask a Spaceman on Twitter or Facebook and ask some questions. Send some questions

about Space My Way. Maybe I'll answer them right away if it's nice and short. Maybe I'll

package them together in like a group show or maybe I'll devote an entire episode on just one

question. That's pretty awesome because we have a very simple goal with this show.

Complete knowledge of time and space. It'll take us a while to get there, but one step at a time.

And today's step is a very cool step. Thanks to Jaita Sarkar at Siza-1-1-1.

On Twitter, she asked,

how were the spiral arms of our Milky Way galaxy formed?

Hashtag Ask a Space man.

That's how I got the question because she put the hashtag there so I knew what was going on.

Thank you so much, Jada, for that question.

Very cool question. Because we see all these

cool galaxies with all these spiral arms and we see in our own Milky Way galaxy, we know that there are

spiral arms in our Milky Way. Even our nearest neighbor, Andromeda, galaxy, have these massive

spiral arms. How in the world do you get spiral arms in a galaxy?

Great question and I hope the answer is as great as the question. Let's start with galaxies

in general. All right. Just how do you form galaxies, period, let alone spirals or ellipticals or regulars or all the other kinds of

galaxies. A long time ago, and that's long with lots of us and theongs, long time ago,

there were no stars in galaxies. There was just gas. Mostly hydrogen, a little bit of helium,

...