Friday, August 7, 2009

The Milky Way

A new mosaic of infrared images taken using NASA's Spitzer Space Telescope gives astronomers a new perspective on our home galaxy. The panoramic view spans 130° along the Milky Way and runs through 13 constellations, from Vulpecula to Centaurus

The Milky Way's center shows up in unprecedented detail in this composite of two galactic-plane surveys from the Spitzer Space Telescope. This view is a small portion of a 800,000 image, 4-billion-pixel mosaic created by combining the GLIMPSE and MIPSGAL surveys. Stars show up as blue, hot gas is green, and warm dust shows up as red. The galactic center is the brightest spot (center)

This artist's rendering illustrates the observing ranges of GLIMPSE as it might appear if viewed from above our Milky Way galaxy. In this rendering, green represents the area captured in the GLIMPSE observations and the yellow dot indicated the location of our solar system. The red slice represents the 9 degrees of sky portrayed in the first panoramic image release from GLIMPSE.

"This majestic view taken by NASA's Spitzer Space Telescope tells an untold story of life and death in the Eagle nebula, an industrious star-making factory located 7,000 light-years away in the Serpens constellation. The image shows the region's entire network of turbulent clouds and newborn stars in infrared light.

The color green denotes cooler towers and fields of dust, including the three famous space pillars, dubbed the "Pillars of Creation," which were photographed by NASA's Hubble Space Telescope in 1995 (see inset). But it is the color red that speaks of the drama taking place in this region. Red represents hotter dust thought to have been warmed by the explosion of a massive star about 8,000 to 9,000 years ago. Since light from the Eagle nebula takes 7,000 years to reach us, this "supernova" explosion would have appeared as an oddly bright star in our skies about 1,000 to 2,000 years ago.

According to astronomers' estimations, the explosion's blast wave would have spread outward and toppled the three pillars about 6,000 years ago (which means we wouldn't witness the destruction for another 1,000 years or so). The blast wave would have crumbled the mighty towers, exposing newborn stars that were buried inside, and triggering the birth of new ones. If a star did blow up in this region, it is probably located among the other massive stars in the upper left portion of the image. Its blast wave might have already caused a third generation of stars to spring from the wreckage of the busted pillars.

This image is a composite of infrared light detected by Spitzer's infrared array camera and multiband imaging photometer. Blue is 4.5-micron light; green is 8-micron light; and red is 24-micron light".

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