Some Thoughts on a Galaxy of Possibilities

I am always amazed at the depth and breadth of discoveries in astronomy that get announced at these AAS meetings. I mean, we all KNOW it’s a big universe and there are always going to be amazing discoveries – but, what we don’t always know is just WHAT those finds will be.

Earlier today we heard from scientists using data from the Sloan Digital Sky Survey to create the largest multicolor image of the night sky. It’s essentially the Palomar Sky Survey of our time, but in digital format. You can browse through their work here, and eventually you’ll see much of their work in GalaxyZoo, World Wide Telescope, and GoogleSky.

As I sat there and listened to the scientists talk about their work, it struck me just how much astronomers learn each DAY and how LITTLE we see about it in the news media.  To be sure, there’s a LOT of news every day, and science has to struggle for attention among all the other events of our time.

Did you know that astronomers are using the Sloan Survey using a technique called “spectroscopy” to look at the light from those stars and figure out their chemical compositions, the velocity (speed) they’re moving through space, and a host of other characteristics?  It’s true.  One of the coolest outcomes of such a study is that they can now tell which stars came from our own galaxy and which ones were or are parts of galaxies that are being sucked into the Milky Way galaxy.  Stars from galaxies being gobbled up have slight differences in their metallicity (the heavier elements they contain), as well as definite variations in their velocities and direction of travel.

These factors, in turn, give astronomers some important clues to how galaxies form – essentially, the Milky Way has gotten bigger by gobbling up stars from smaller galaxies that were once neighbors moving along the cosmic highway with it. Trace the characteristics of those stars spectroscopically and you learn more about the former neighbor satellites that are now mingling their stars with the Milky Way Galaxy.

Well… THAT was just one tiny part of what Sloan Digital Sky Survey scientists discussed this morning–just a small drip from the firehose of astronomy information flowing at this meeting.  There is literally a galaxy of science to be learned here.