ESA Planck scanning - Galactic, mollweide

The ring of sky which the Planck satellite scans at any one time is shown as a white ring. As it orbits the Sun, it maps out the sky, shown here as the sky as measured by the WMAP satellite (credit NASA/WMAP Science Team).

The map is shown in Galactic coordinates, aligned with the plane of our Galaxy, and projected in a "Mollweide" projection, meaning that entire sky is shown in one oval, just like in some maps of the world in an Atlas.

The solar system is tilted relative to the plane of the Galaxy, so the ring which Planck scans moves oddly around the sky in this view.

http://planck.cf.ac.uk/scanning