Scite of the Day

Now this might not actually happen every day, and it might not always be science. But I expect it will happen most days and be mostly science-oriented. Today's site is the classic Astronomy Picture of the Day- APOD. Today's picture happens to be of the highly cratered face of Rhea, a moon of Saturn. Most of the APOD pictures are reduced in size. Click the pic to expand to the full version; the resolution and detail can be breath-taking. The archive has all the pictures that have been posted over the years.

Check out yesterday's picture too: a gorgeous shot of galaxies of the M81 group seen through wispy fog of a nebula. If you expand the picture to the full size, and look at the spiral galaxy near the center, you will notice that the outer part is distinctly more blue while the central parter is yellower. Blue stars "burn" hotter and faster, and are short-lived as stars go- a few tens or hundreds of million years. (our sun by comparison is about 4600 million years old) So blue stars die off pretty quickly, leaving yellow and red stars as the only survivors. When you see distinct color differences in parts of a galaxy (and if you look for them, you'll see such color variations frequently), you can tell at a glance which are the active star-forming regions (the bluer areas with many young, hot stars), and which are the older, calmer retirement communities.