Microwave Sky

Microwave Sky
This map of the microwave sky was produced from data taken by instruments on board COBE. The galactic center is in the middle of the map, and the plane
of the Milky Way runs horizontally across the map. Color indicates Doppler shift and temperature: Blue is where the microwave background is blueshifted
and appears warmer, while red is where it is redshifted and appears cooler. This Doppler shift across the sky is caused by Earth’s motion through the
microwave background. The resulting variation in background temperature is quite small, only 0.0033 K above the average radiation temperature of 2.726 K