Dramatic change spotted on a faraway planet

In this episode of the Hubblecast, Dr J (aka Dr Joe Liske) presents the latest discovery about HD 189733b, an exoplanet that has been repeatedly studied by Hubble. Observations taken in 2011 using Hubble and the Swift satellite showed a flare from the planet’s parent star scorching the upper atmosphere and driving it off into space. This is the first time that clear change has been observed in an exoplanet’s atmosphere. The observations give a tantalising glimpse of changing weather on planets outside our Solar System.