The aurora borealis (to the north, and australis to the south of the Earth) are the most spectacular phenomena of a chain that connects the planet’s upper atmosphere to the solar activity. In this lecture, the speaker addresses the questions they raise: What solar origin ? What interaction between the solar wind and the space environment ? How are they formed? What are they witnessing? Do they exist elsewhere than on Earth? What research is still being done on auroras?
Jean Lilensten is currently senior researcher at the Institut de Planétologie et d’Astrophysique de Grenoble, France. At the beginning of the 90s, the scientific community working on the solar terrestrial relationships, had a relatively circumscribed field of research. Two major evolutions have marked it considerably. The first is space weather which aims at extending the scientific knowledge in order to be able to quantify the solar activity and its impacts on our societies. The second is comparative planetology. In the recent years, these currents seem to join together to form a “planetary space weather”. Jean Lilensten developed his research in both branches, addressing the impact of solar activity on different planets (Earth, Mars, Venus, Jupiter, Saturn). Amongst his most recent discoveries are the existence of blue auroras at Mars, and the polarisation of the auroral and nightglow emission at Earth. He published 15 books ranging from space weather to epistemology.
Webinar was recorded on January 12, 2023