Filamentary structures on large and small scales in the Milky Way

Filamentary structures are apparent on large scales (as shown in the Planck image, right) and small scales (as seen in the Herschel image of a region in the Aquila constellation, left) in the Milky Way. The Planck image, covering a portion of the sky about 55°, was obtained by the High Frequency Instrument at a frequency of 857 GHz (corresponding to a wavelength of 350 micrometres). The dark horizontal band is the plane of our Galaxy, seen in cross-section from our vantage point. The colours represent the intensity of heat radiation by dust. The Planck image was obtained during the First Planck All-Sky Survey, which began in mid-August 2009 and is being completed now. By mid-March 2010, 98% of the sky had been observed by Planck, and 100% sky coverage is expected by late May 2010.