Temperature of the Sun. Stereoscopic 3D image of the Sun's south pole, made by combining observations in three wavelengths (171, 195 and 304 angstroms) of ultraviolet (UV) light. These have then been mapped to the red blue and green visible portion of the spectrum to emphasize the temperature difference of the solar material. Two images (left-sided and right-sided) were taken with the Extreme UltraViolet Imager (EUVI) on NASA's STEREO (Solar TErrestrial RElations Observatory) satellites, one by STEREO-A and one by STEREO-B, and combined to produce the 3D image.