Hubble’s Space Telescope Imaging Spectrograph measured changes in the color of light from the planet before, during and after a pass behind its star. There was a small drop in light and a slight change in the color of the light. The research team said that they absorbed the light becoming less bright in the blue but not in the green or red. Light was missing in the blue but not in the red when it was hidden.
This means that the object that disappeared was blue. Earlier observations have reported evidence for scattering of blue light on the planet. The latest Hubble observation confirms the evidence. On this alien world, the daytime temperature is nearly 2,000 degrees Fahrenheit, and it possibly rains glass sideways in howling, 4,500-mph winds. Hubble and other observatories have made intensive studies of HD 189733b and its atmosphere is changeable and exotic. HD 189733b is among a bizarre class of planets called hot Jupiter, which orbit close to their parent stars.