HFI and LFI maps and differences. Top: north ecliptic pole region. The four panels are: upper-left, 70 GHz; lower-right, 100 GHz; upper-right, 100 GHz − 70 GHz; and lower-left, difference of 70 GHz half-ring and 100 GHz half-mission difference maps. The frequency difference map demonstrates excellent visual consistency of the measured CMB anisotropies, and reveals diffuse foregrounds and point sources, specifically positive dust and CO emission and negative free-free and synchrotron emission. Note the large Cygnus region in the Galactic plane. Bottom: south Galactic pole region, with the same 4-panel layout as for the top part. We note the dust haze in the upper right part of the difference panel and the large, negative CMB fluctuation in the upper left of the 70 and 100 GHz frequency maps, called the Cold Spot.