Picture of the day - August 15, 2008

The beautiful "Cat's Eye Nebula"

Photo courtesy of NASA. When stars run out of hydrogen fuel, they don't simply fade into the darkness like the dying embers of a campfire. Instead, they put on a dazzling show, the likes of which depend on their masses. Large stars with masses more than 8 times the mass of our own sun literally explode. These "supernova" explosions have been witnessed from earth many times over the eons, causing fear and uncertainty to spread around the planet in times past because those who witnessed them had no idea what they were. But smaller stars like the sun don't suffer the fate of a supernova explosion... Instead, they become red giants as the temperature of the core heats up to, well...astronomical levels. The outer layers of expanded gases are eventually cast off into space leaving the star's core and the intense visible light and X-ray energy it is emitting easily visible to telescopes and scientific instruments. This planetary nebula phase of a star's life typically gives us our last "view" of the star before it ultimately goes dark. Today's picture features the beautiful "Cat's Eye Nebula", one of the most colorful objects in the known universe.   Click here to comment on this picture.   Visit the POTD Archives for previous "Pictures Of The Day"!     Submit a photo of your own!                                 Place the "Picture of the Day" on your website, for free! Why I publish the "Picture of the Day"