Figure 2-11 The Sun as a Blackbody This graph shows that the intensity of sunlight over a wide range of wavelengths (solid curve) is a remarkably close match to the intensity of light coming from a blackbody at a temperature of 5800 K (dashed curve). The measurements of the Sun’s intensity were made above Earth’s atmosphere (which absorbs and scatters certain wavelengths of sunlight). It is not surprising that the range of visible wavelengths includes the peak of the Sun’s spectrum; the human eye evolved to take advantage of the most plentiful light available.