Scientists from the Paris Observatory used the NASA/ESA Hubble Space Telescope to take a look at the auroras on Uranus, which are caused by streams of charged particles like electrons that come from various origins such as solar winds, the planetary ionosphere, and moon volcanism. The particles become caught in powerful magnetic fields and are channelled into the upper atmosphere, where their interactions with gas particles, such as oxygen or nitrogen, set off spectacular bursts of light.
The auroras on Jupiter and Saturn have been well-studied, but the auroras on the giant ice planet Uranus remain something of a mystery. The first images of Uranus taken from Earth were shot in 2011 by the NASA Hubble. In 2012 and 2014 a team led by an astronomer from Paris Observatory took a second look at the auroras using the ultraviolet capabilities of the Space Telescope Imaging Spectrograph (STIS) installed on Hubble.
They tracked the interplanetary shocks caused by two powerful bursts of solar wind travelling from the sun to Uranus, then used Hubble to capture their effect on Uranus’ auroras – and found themselves observing the most intense auroras ever seen on the planet. By watching the auroras over time, they collected the first direct evidence that these powerful shimmering regions rotate with the planet.
The Uranus aurora images were revealed recently and they are a mixture of the old images and the new ones. The photograph of the orbiting disk of the planet came from the photos that Voyager 2 took and the aurora came from the pictures taken by the Hubble telescope. Both sets offer a stunning look at a planet that brings about many giggles due to the mispronounced name.