Wednesday, December 5, 2012

Call the Cosmic Police, the universe is speeding!

NASA’s Spitzer telescope, a product of the great observatories program, has enabled a more accurate estimation of the speed of the universe and it is fast! 74.3 plus or minus 2.1 kilometers per second per megaparsec is the precise rate as discovered by the Spitzer Telescope.

Ever since Hubble’s initial discovery, scientists have been trying to refine their equation that expresses the expansion rate, changing the Hubble constant’s accuracy to within 3%. The exciting thing is that this also sheds light on our understanding of Dark Energy and its battle with the gravity that pulls the universe outward. Now these scientists are measuring Dark Energy from another point of view.

Pictured above is a graph of the Cepheid period and its relationship to the Cepheid luminosity. From there the intrinsic brightness and perceived or observed brightness can be determined, and compared and that’s how we get a star’s distance. It is these distance measurements that are being used to measure the expansion of the universe. It is not rocket science, its Cosmology and very cool in its own right,

The Spitzer Telescope that made all this possible was launched in 2003 and in 2009 ran out of the special coolant used to cool down the instruments. But all is not lost. Without the coolant, the Spitzer is unable to see all the wavelengths that it originally could, but its mission isn’t over yet, it has a second mission, a warmer mission. Now it contributes greatly to scientist’s knowledge of Stars, Planet Forming Discs, Exoplanets and galaxies and the origins of the universe. No rest for the weary especially in a big universe that is getting bigger.

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