Cool image time! In anticipation of the arrival of Juno in orbit around Jupiter on July 4, scientists have released a spectacular image of Jupiter and its aurora, taken by the Hubble Space Telescope. The image on the right has been reduced slightly to fit on the webpage.

The main focus of the imaging is the aurora.

To highlight changes in the auroras, Hubble is observing Jupiter almost daily for several months. Using this series of far-ultraviolet images from Hubble’s Space Telescope Imaging Spectrograph, it is possible for scientists to create videos that demonstrate the movement of the vivid auroras, which cover areas bigger than the Earth.

Not only are the auroras huge in size, they are also hundreds of times more energetic than auroras on Earth. And, unlike those on Earth, they never cease. While on Earth the most intense auroras are caused by solar storms — when charged particles rain down on the upper atmosphere, excite gases, and cause them to glow red, green, and purple — Jupiter has an additional source for its auroras.

The strong magnetic field of the gas giant grabs charged particles from its surroundings. This includes not only the charged particles within the solar wind, but also the particles thrown into space by its orbiting moon Io, known for its numerous and large volcanos.

I have embedded below the fold one of the videos of the aurora, taken over time by Hubble. Quite amazing.