Thursday, February 10, 2011

Thursday's wonder

Whoa. This is where stars are born. This is a new image of the North America Nebula from NASA's Spitzer Space Telescope. You can see the massive full size image here. Why is this important? - in all likelihood our Sun and its planets formed in a nebular cloud very much like this one.

Each little pinpoint speck of light in Spitzer's image is a young star at some particular point in its development., and haven't even become true stars yet—that only occurs when thermonuclear fusion kicks off in their cores. Others have begun their stardom, but are still sheathed in spherical cocoons of gas and dust, shells of material that will gradually grow puffy and vaporous from the inner star's light and heat, until they whisper away on stellar winds. Many of these points of light are ringed by thick accretion disks of material that formed from the angular momentum of their initial gravitational collapse. Sometimes parts of the disk get sucked too close to the star, and are shocked into plasma and spun away and out from the star's poles in powerful collimated jets that can sculpt and shape the surrounding gas and dust into abstract whorls and tendrils. And, in the background, almost unnoticed against all the stellar fireworks, in all probability planets are slowly and surely forming. Perhaps, on a few them, the seeds of life are already being sown by comets and meteorites, the infalling detritus of star formation delivering water and complex chemical compounds brewed in the stellar clouds. Some are still undergoing their initial gravitational collapse.


I tried to find a website that could explain where the  North America Nebula was in easy to understand terms and found just what I was looking for here. Unfortunately I then kept zooming out until my head exploded.

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