Differential microwave Radiometer

 4-year full-sky temperature map of the cosmic microwave background, in Galactic coordinates. The dipole variation due to Solar System motion has been removed. The equatorial band is foreground Milky Way radiation. Elsewhere the colors indicate fluctuations of tens of microkelvin. The DMR's angular resolution is 7°. The blowups of a7° circle indicate the finer detail that might be revealed by the next-generation MAP and Planck satellites: The left blowup simulates an open universe (Ω= 0.1); the right blowup simulates the flat universe (Ω = 1) preferred by inflationary theories.