The auroral phenomenon: more common than you might think

How does the discovery of “isolated” aurorae on Venus and Mars advance astronomy or physics? “This is likely a process that is happening in billions of places across the universe, on exoplanets that have lost their global magnetic field,” explains Jean-Claude Gérard. “Every time a planet’s core cools down quickly, especially due to the planet’s small size, its magnetic field disappears. Our discovery on the Red Planet, which no longer has a global magnetic field, provides a model for what might happen on the many exoplanets of low mass and size that have an atmosphere.”

The objective of cataloguing the various types of aurorae will help understanding the interactions between planets, their atmospheres, solar wind, the behaviour of charged particles… these processes cannot quite be simulated in a laboratory. In fact, our Earth is like a gigantic laboratory involving the Sun, its distance from the planet, the planet’s magnetic field, the composition of the atmosphere… Lauriane Soretʼs goal as she studies various aurora phenomena is to gain a general understanding of the processes involved, with universal rules that apply to different conditions. The common theme is the behaviour of the atmosphere in which auroral glows appear.

The study of auroral phenomena will continue to be a part of our exploration of the solar system. In the future more than ever,  LPAP will follow the next scientific missions that will help understand these phenomena, with research on Jupiter’s enormous aurorae being planned using data from NASAʼs and ESAʼs probes. Juno has been en route towards the largest planet in the solar system since August 5, 2011, and it will be inserted into orbit on July 4, 2016. It is equipped with imaging spectrometers UVS and JIRAM (Jovian Infrared Auroral Mapper), which will provide close-up measurements of Jupiter’s aurorae. ESAʼs planned JUICE mission should focus on Jupiter’s aurorae, but also on those of its moons Europa and Ganymede. The latter has its own magnetic field, like Jupiter.

The researchers at LPAP in Liège and BIRA-IASB in Brussels have already taken action to advance the study of light phenomena that occur in planets’ atmospheres, as a part of a collaboration between universities and federal institutes. Belgium’s scientific policy has selected, among the thematic initiatives for interdisciplinary networks, the SCOOP project (towards a SynergistiC study Of the atmOsphere of terrestrial Planets). Starting in March, 2015 and lasting four years, this project will use – among other things – the data obtained from the NOMAD instrument on board ExoMars TGO probe, to be launched in 2016. This means that aurora hunters will have plenty to feast their eyes on for the coming decades.