AAS Report #2: Dark matter and large scale structure

A note: I am attending a meeting of the American Astronomical Society in Seattle. I will blog as much as I can from this meeting, as there is a LOT of news coming out, as well as lots of fun and wonderful scientific geekiness. This particular blog entry is a bit long as I have to explain some relatively complex things to get to the point. I think most of my reporting will be somewhat less wordy. But no promises! I love this stuff, and I love to talk about it. Today, astronomers released news about the largest and most detailed survey of the deep Universe ever made. It used telescopes in space and on the ground to make a huge census of matter across the Universe, from local regions out to a distance of about 6 billion light years. It's called COSMOS, for the Cosmic Evolution Survey, the telescopes involved were Hubble, XMM-Newton, Spitzer, Keck, the Very Large Telescope in Chile, the Very Large (radio telescope) Array in New Mexico, and the Subaru observatory. It involved over 100 scientists from more than a dozen countries. This survey is incredible: it mapped the location of more than two million galaxies over an area two degrees on a side on the sky-- bigger than 16 full Moons. In the end, astronomers made what is essentially a three-dimensional large-scale map of normal matter (the stuff that makes up you, me, doorknobs, snakes, planes, everything we can see and touch). Here's a (very) small piece of the survey image from Hubble: