  The largest uncollapsed inhomogeneity in the observable Universe is
statistically represented in the quadrupole signal of the cosmic microwave
background (CMB) sky maps as observed by the Wilkinson Microwave Anisotropy
Probe (WMAP). The constant temporal offset of -25.6 ms between the timestamps
of the spacecraft attitude and observational data records in the time-ordered
data (TOD) of the WMAP observations was suspected to imply that previously
derived all-sky CMB maps are erroneous, and that the quadrupole is in large
part an artefact. The optimal focussing of bright objects in the Galactic Plane
plays a key role in showing that no error occurred at the step of mapmaking
from the calibrated TOD. Instead, the error had an effect when the uncalibrated
TOD were calibrated. Estimates of the high-latitude quadrupole based on the
wrongly calibrated WMAP maps are overestimated by about 15-60%.
