The ULg’s Atmospherical and Planetary Physics Laboratory (LPAP) has been involved in the hunt for aurora on the Jupiter and Saturn giants from the beginning. Its reputation in this domain no longer brooks any discussion. And this new auroral footprint discovery will only increase scientists’ interest in these observations. ‘Up until very recently it was thought that the Io-Jupiter duo was unique,’ explains Denis Grodent. ‘The detection of Ganymede’s auroral footprint on Jupiter and now that of Enceladus on Saturn changes the whole situation: the phenomenon seems relatively universal throughout the solar system and also surely in the context of exoplanets. Detecting the signals of an interaction between a satellite and its planet could in the future become a means of detecting a satellite around an exoplanet, but also a tool for characterising the atmosphere or the rotation speed of an exoplanet which provides a home for natural satellites.’

The Cassini is playing extra time as it should continue up until 2017, whilst initially the mission was only planned to last for a few years. ‘In a few months there will be a new Saturn observation campaign, involving both Cassini and the Hubble space telescope,’ announces Jean-Claude Gérard. ‘With the two instruments we will simultaneously take three sequences of measurements in the first quarter of 2011. The goal will be to measure the temperature of Saturn in the polar regions, something which has never been done.’ It should also be pointed out that next August will also see the launch of the JUNO satellite, a project which has involved the Liège Space Centre as well as the LPAP. It will travel to Jupiter to study its gravitational and magnetic fields. JUNO will be the first instrument to study Jupiter’s poles, allowing us to expect beautiful auroral images similar to those of Saturn transmitted by Cassini. As will by now be clear, auroral observations will be on the agenda for many years to come.