Sunrise on HD 189733b (artist’s impression)

This artist’s impression shows a viewpoint rising up through the atmosphere of exoplanet HD 189733b during sunrise. The colours of the blue sky and reddish star are caused by Rayleigh scattering, the same effect that produces blue skies and red sunsets on Earth. This effect is produced by haze in the upper atmosphere scattering blue light more efficiently than red. The colours in the video are derived from estimates by Frederic Pont (Exeter University, UK) and Alain Lecavelier des Etangs (IAP/CNRS, France), based on Hubble observations of HD 189733b’s atmosphere.