Here's the latest article from the Astronomy site at BellaOnline.com.
What Is a Galaxy
What is a galaxy? A great star system held together by gravity, with stars, gas and dust, black holes and dark matter. Astronomers used to think our Galaxy was the whole universe. But now that we know of billions of galaxies, they're considered to be the building blocks of the universe.
*Monster spiral galaxy*
The biggest galaxies are still giant elliptical galaxies in the middle of clusters. But one of the findings presented at the annual meeting of the American Astronomical Society this week was of a pretty big spiral galaxy. BGC 6872 has always been considered one of the biggest known spiral galaxy, but studying it in ultraviolet light has shown that it's much bigger than anyone thought. It's now been measured at 522,000 light years across. (That's five times the size of the Milky Way.) Here is an image: http://ut-images.s3.amazonaws.com/wp-content/uploads/2013/01/718351main_composite_labels_673-580x325.jpg
*The man who can fly*
A short video of a daring climber walking a highline at Cathedral Peak in Yosemite National Park. The camerman is some distance away to get an astounding perspective on Dean Potter and a rising full moon. It's part of a National Geographic project and is worth a look: http://vimeo.com/56298775
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