Filamentary structures in our Milky Way galaxy are apparent at large scales (as shown in this Planck image, on the right) and small scales (as seen in the Herschel image on the left).
This Planck image, covering a portion of the sky about 55 degrees in total extent, was obtained by the Planck High Frequency Instrument at a frequency of 857 Gigahertz (corresponding to a wavelength of 350 micrometers). The bright horizontal band corresponds to the plane of our spiral galaxy, which is seen in cross-section from our vantage point. The colors in the Planck images represent the intensity of heat radiation by dust.
This Planck image was obtained during the first Planck all-sky survey, which began in mid-August 2009. By mid-March 2010, more than 98 percent of the sky had been observed. The second sky scan is underway, but, because of the way Planck surveys the sky, the first scan won't be 100 percent complete until late-May 2010.
Image credit: ESA and the HFI Consortium.
Image credit (for inset): ESA and the SPIRE & PACS consortia, P. André (CEA Saclay) for the Gould's Belt Key Programme Consortium